MT8889CE1 [MICROSEMI]

DTMF Signaling Circuit, CMOS, PDIP20, LEAD FREE, PLASTIC, MS-001AD, DIP-20;
MT8889CE1
型号: MT8889CE1
厂家: Microsemi    Microsemi
描述:

DTMF Signaling Circuit, CMOS, PDIP20, LEAD FREE, PLASTIC, MS-001AD, DIP-20

电信 光电二极管 电信集成电路
文件: 总24页 (文件大小:513K)
中文:  中文翻译
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MT8889C  
Integrated DTMF Transceiver  
with Adaptive Micro Interface  
Data Sheet  
July 2008  
Features  
Central office quality DTMF transmitter/receiver  
Ordering Information  
Low power consumption  
MT8889CE  
MT8889CS  
MT8889CN  
MT8889CE1  
MT8889CS1  
MT8889CN1  
MT8889CSR  
20 Pin PDIP  
20 Pin SOIC  
24 Pin SSOP  
20 Pin PDIP*  
20 Pin SOIC*  
24 Pin SSOP*  
20 Pin SOIC  
Tubes  
Tubes  
High speed adaptive micro interface  
Adjustable guard time  
Tubes  
Tubes  
Tubes  
Tubes  
Automatic tone burst mode  
Tape & Reel  
Tape & Reel  
MT8889CSR1 20 Pin SOIC*  
*Pb Free Matte Tin  
Call progress tone detection to -30 dBm  
-40°C to +85°C  
Applications  
Credit card systems  
Paging systems  
The receiver section is based upon the industry  
standard MT8870 DTMF receiver while the transmitter  
utilizes a switched capacitor D/A converter for low  
distortion, high accuracy DTMF signalling. Internal  
counters provide a burst mode such that tone bursts  
can be transmitted with precise timing. A call progress  
filter can be selected allowing a microprocessor to  
analyze call progress tones.  
Repeater systems/mobile radio  
Interconnect dialers  
Personal computers  
Description  
The MT8889C utilizes an adaptive micro interface,  
which allows the device to be connected to a number  
of popular microcontrollers with minimal external logic.  
The MT8889C is a monolithic DTMF transceiver with  
call progress filter. It is fabricated in CMOS technology  
offering low power consumption and high reliability.  
D0  
Data  
Bus  
Buffer  
Row and  
D/A  
Transmit Data  
D1  
D2  
D3  
Column  
TONE  
Converters  
Register  
Counters  
Status  
Register  
Interrupt  
Logic  
Tone Burst  
Gating Cct.  
Control  
Logic  
IRQ/CP  
Control  
Register  
A
IN+  
IN-  
GS  
+
-
Dial  
Tone  
Filter  
High Group  
Filter  
Digital  
DS/RD  
CS  
Algorithm  
and Code  
Converter  
Control  
Register  
B
I/O  
Low Group  
Filter  
Control  
OSC1  
OSC2  
Oscillator  
R/W/WR  
RS0  
Circuit  
Control  
Logic  
Receive Data  
Register  
Steering  
Logic  
Bias  
Circuit  
VDD VRef VSS  
ESt  
St/GT  
Figure 1 - Functional Block Diagram  
1
Zarlink Semiconductor Inc.  
Zarlink, ZL and the Zarlink Semiconductor logo are trademarks of Zarlink Semiconductor Inc.  
Copyright 2003-2008, Zarlink Semiconductor Inc. All Rights Reserved.  
MT8889C  
Data Sheet  
Functional Description  
The MT8889C Integrated DTMF Transceiver consists of a high performance DTMF receiver with an internal gain  
setting amplifier and a DTMF generator, which employs a burst counter to synthesize precise tone bursts and  
pauses. A call progress mode can be selected so that frequencies within the specified passband can be detected.  
The adaptive micro interface allows microcontrollers, such as the 68HC11, 80C51 and TMS370C50, to access the  
MT8889C internal registers.  
24  
23  
22  
21  
20  
19  
18  
17  
16  
15  
14  
13  
IN+  
IN-  
GS  
VRef  
VSS  
OSC1  
OSC2  
NC  
NC  
TONE  
R/W/WR  
CS  
1
2
3
4
5
6
7
8
VDD  
St/GT  
ESt  
D3  
D2  
D1  
D0  
NC  
NC  
20  
19  
18  
17  
16  
15  
14  
13  
12  
11  
1
2
3
4
5
6
7
8
IN+  
IN-  
GS  
VRef  
VSS  
VDD  
St/GT  
ESt  
D3  
D2  
D1  
D0  
IRQ/CP  
DS/RD  
RS0  
NC  
VRef  
VSS  
OSC1  
OSC2  
NC  
NC  
NC  
NC  
D3  
D2  
D1  
D0  
5
25  
24  
23  
22  
21  
20  
19  
6
7
8
9
OSC1  
OSC2  
TONE  
R/W/WR  
CS  
10  
11  
NC  
9
9
10  
10  
11  
12  
IRQ/CP  
DS/RD  
RS0  
20 PIN PLASTIC DIP/SOIC  
24 PIN SSOP  
28 PIN PLCC  
Figure 2 - Pin Connections  
Pin Description  
Pin #  
24  
Name  
Description  
20  
28  
1
2
3
1
2
3
1
2
4
IN+  
IN-  
GS  
Non-inverting op-amp input.  
Inverting op-amp input.  
Gain Select. Gives access to output of front end differential amplifier for  
connection of feedback resistor.  
4
5
6
4
5
6
6
7
8
VRef  
VSS  
Reference Voltage output (VDD/2).  
Ground (0V).  
OSC1 DTMF clock/oscillator input. Connect a 4.7 Mresistor to VSS if crystal oscillator  
is used.  
7
7
9
OSC2 Oscillator output. A 3.579545 MHz crystal connected between OSC1 and OSC2  
completes the internal oscillator circuit. Leave open circuit when OSC1 is driven  
externally.  
8
9
10  
11  
12  
12  
TONE Output from internal DTMF transmitter.  
13 R/W (WR) (Motorola) Read/Write or (Intel) Write microprocessor input. TTL compatible.  
10  
14  
CS  
Chip Select input. This signal must be qualified externally by either address  
strobe (AS), valid memory address (VMA) or address latch enable (ALE) signal,  
see Figure 14.  
11  
12  
13  
14  
15  
17  
RS0  
Register Select input. Refer to Table 3 for bit interpretation. TTL compatible.  
DS (RD) (Motorola) Data Strobe or (Intel) Read microprocessor input. Activity on this  
input is only required when the device is being accessed. TTL compatible.  
2
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
Pin Description (continued)  
Pin #  
Name  
Description  
20  
24  
28  
13  
15  
18  
IRQ/CP Interrupt Request/Call Progress (open drain) output. In interrupt mode, this  
output goes low when a valid DTMF tone burst has been transmitted or received.  
In call progress mode, this pin will output a rectangular signal representative of  
the input signal applied at the input op-amp. The input signal must be within the  
bandwidth limits of the call progress filter, see Figure 8.  
14-17 18-21 19-22  
D0-D3 Microprocessor data bus. High impedance when CS = 1 or DS =0 (Motorola) or  
RD = 1 (Intel). TTL compatible.  
18  
19  
22  
23  
26  
27  
ESt  
Early Steering output. Presents a logic high once the digital algorithm has  
detected a valid tone pair (signal condition). Any momentary loss of signal  
condition will cause ESt to return to a logic low.  
St/GT Steering Input/Guard Time output (bidirectional). A voltage greater than VTSt  
detected at St causes the device to register the detected tone pair and update the  
output latch. A voltage less than VTSt frees the device to accept a new tone pair.  
The GT output acts to reset the external steering time-constant; its state is a  
function of ESt and the voltage on St.  
20  
24  
28  
VDD  
NC  
Positive power supply (5 V typical).  
No Connection.  
8, 9, 3,5,10,  
16,17 11,16,  
23-25  
1.0 Input Configuration  
The input arrangement of the MT8889C provides a differential-input operational amplifier as well as a bias source  
(VRef), which is used to bias the inputs at VDD/2. Provision is made for connection of a feedback resistor to the op-  
amp output (GS) for gain adjustment. In a single-ended configuration, the input pins are connected as shown in  
Figure 3.  
Figure 4 shows the necessary connections for a differential input configuration.  
2.0 Receiver Section  
Separation of the low and high group tones is achieved by applying the DTMF signal to the inputs of two sixth-order  
switched capacitor bandpass filters, the bandwidths of which correspond to the low and high group frequencies  
(see Table 1). The filters also incorporate notches at 350 Hz and 440 Hz for exceptional dial tone rejection. Each  
filter output is followed by a single order switched capacitor filter section, which smooths the signals prior to limiting.  
Limiting is performed by high-gain comparators which are provided with hysteresis to prevent detection of  
unwanted low-level signals. The outputs of the comparators provide full rail logic swings at the frequencies of the  
incoming DTMF signals.  
3
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
IN+  
IN-  
RIN  
C
GS  
RF  
VRef  
MT8889C  
VOLTAGE GAIN  
(AV) = RF / RIN  
Figure 3 - Single-Ended Input Configuration  
IN+  
IN-  
C1  
C2  
R1  
R4  
R5  
R2  
GS  
R3  
VRef  
MT8889C  
DIFFERENTIAL INPUT AMPLIFIER  
C1 = C2 = 10 nF  
R1 = R4 = R5 = 100 kΩ  
R2 = 60k, R3 = 37.5 kΩ  
R3 = (R2R5)/(R2 + R5)  
VOLTAGE GAIN  
(AV diff) - R5/R1  
INPUT IMPEDANCE  
(ZINdiff) = 2 R12 + (1/ωC)2  
Figure 4 - Differential Input Configuration  
FLOW  
FHIGH  
1209  
DIGIT  
D3  
D2  
D1  
D0  
697  
697  
697  
770  
770  
770  
1
2
3
4
5
6
0
0
0
0
0
0
0
0
0
1
1
1
0
1
1
0
0
1
1
0
1
0
1
0
1336  
1477  
1209  
1336  
1477  
Table 1 - Functional Encode/Decode Table  
4
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
FLOW  
FHIGH  
1209  
DIGIT  
D3  
D2  
D1  
D0  
852  
852  
852  
941  
941  
941  
697  
770  
852  
941  
7
8
9
0
*
0
1
1
1
1
1
1
1
1
0
1
0
0
0
0
1
1
1
1
0
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1336  
1477  
1336  
1209  
1477  
1633  
1633  
1633  
1633  
#
A
B
C
D
Table 1 - Functional Encode/Decode Table (continued)  
0= LOGIC LOW, 1= LOGIC HIGH  
Following the filter section is a decoder employing digital counting techniques to determine the frequencies of the  
incoming tones and to verify that they correspond to standard DTMF frequencies. A complex averaging algorithm  
protects against tone simulation by extraneous signals such as voice while providing tolerance to small frequency  
deviations and variations. This averaging algorithm has been developed to ensure an optimum combination of  
immunity to talk-off and tolerance to the presence of interfering frequencies (third tones) and noise. When the  
detector recognizes the presence of two valid tones (this is referred to as the “signal condition” in some industry  
specifications) the “Early Steering” (ESt) output will go to an active state. Any subsequent loss of signal condition  
will cause ESt to assume an inactive state.  
3.0 Steering Circuit  
Before registration of a decoded tone pair, the receiver checks for a valid signal duration (referred to as character  
recognition condition). This check is performed by an external RC time constant driven by ESt. A logic high on ESt  
causes vc (see Figure 5) to rise as the capacitor discharges. Provided that the signal condition is maintained (ESt  
remains high) for the validation period (tGTP), vc reaches the threshold (VTSt) of the steering logic to register the  
tone pair, latching its corresponding 4-bit code (see Table 1) into the Receive Data Register. At this point the GT  
output is activated and drives vc to VDD. GT continues to drive high as long as ESt remains high. Finally, after a  
short delay to allow the output latch to settle, the delayed steering output flag goes high, signalling that a received  
tone pair has been registered. The status of the delayed steering flag can be monitored by checking the appropriate  
bit in the status register. If Interrupt mode has been selected, the IRQ/CP pin will pull low when the delayed  
steering flag is active.  
The contents of the output latch are updated on an active delayed steering transition. This data is presented to the  
four bit bidirectional data bus when the Receive Data Register is read. The steering circuit works in reverse to  
validate the interdigit pause between signals. Thus, as well as rejecting signals too short to be considered valid, the  
receiver will tolerate signal interruptions (drop out) too short to be considered a valid pause. This facility, together  
with the capability of selecting the steering time constants externally, allows the designer to tailor performance to  
meet a wide variety of system requirements.  
5
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
VDD  
MT8889C  
C1  
VDD  
Vc  
St/GT  
ESt  
R1  
tGTA = (R1C1) In (VDD / VTSt  
)
tGTP = (R1C1) In [VDD / (VDD-VTSt)]  
Figure 5 - Basic Steering Circuit  
Guard Time Adjustment  
The simple steering circuit shown in Figure 5 is adequate for most applications. Component values are chosen  
according to the following inequalities (see Figure 7):  
tREC tDPmax + tGTPmax - tDAmin  
tREC tDPmin + tGTPmin - tDAmax  
tID tDAmax + tGTAmax - tDPmin  
tDO tDAmin + tGTAmin - tDPmax  
t
GTP = (RPC1) In [VDD / (VDD-VTSt)]  
GTA = (R1C1) In (VDD/VTSt  
P = (R1R2) / (R1 + R2)  
t
)
R
VDD  
C1  
St/GT  
R1  
R2  
ESt  
a) decreasing tGTP; (tGTP < tGTA)  
tGTP = (R1C1) In [VDD / (VDD-VTSt)]  
tGTA = (RpC1) In (VDD/VTSt  
RP = (R1R2) / (R1 + R2)  
)
VDD  
C1  
St/GT  
R1  
R2  
b) decreasing tGTA; (tGTP > tGTA)  
ESt  
Figure 6 - Guard Time Adjustment  
6
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
The value of tDP is a device parameter (see AC Electrical Characteristics) and tREC is the minimum signal duration  
to be recognized by the receiver. A value for C1 of 0.1 µF is recommended for most applications, leaving R1 to be  
selected by the designer. Different steering arrangements may be used to select independent tone present (tGTP  
)
and tone absent (tGTA) guard times. This may be necessary to meet system specifications which place both accept  
and reject limits on tone duration and interdigital pause. Guard time adjustment also allows the designer to tailor  
system parameters such as talk off and noise immunity.  
Increasing tREC improves talk-off performance since it reduces the probability that tones simulated by speech will  
maintain a valid signal condition long enough to be registered. Alternatively, a relatively short tREC with a long tDO  
would be appropriate for extremely noisy environments where fast acquisition time and immunity to tone drop-outs  
are required. Design information for guard time adjustment is shown in Figure 6. The receiver timing is shown in  
Figure 7 with a description of the events in Figure 9.  
4.0 Call Progress Filter  
A call progress mode, using the MT8889C, can be selected allowing the detection of various tones, which identify  
the progress of a telephone call on the network. The call progress tone input and DTMF input are common,  
however, call progress tones can only be detected when CP mode has been selected. DTMF signals cannot be  
detected if CP mode has been selected (see Table 7). Figure 8 indicates the useful detect bandwidth of the call  
progress filter. Frequencies presented to the input, which are within the ‘accept’ bandwidth limits of the filter, are  
hard-limited by a high gain comparator with the IRQ/CP pin serving as the output. The squarewave output obtained  
from the schmitt trigger can be analyzed by a microprocessor or counter arrangement to determine the nature of  
the call progress tone being detected. Frequencies which are in the ‘reject’ area will not be detected and  
consequently the IRQ/CP pin will remain low.  
EVENTS  
A
B
C
D
E
F
tREC  
tDO  
tID  
tREC  
TONE  
#n + 1  
TONE  
#n + 1  
TONE #n  
Vin  
tDA  
tDP  
ESt  
tGTP  
tGTA  
VTSt  
St/GT  
tPStRX  
RX0-RX3  
b3  
DECODED TONE # (n-1)  
# (n + 1)  
# n  
tPStb3  
b2  
Read  
Status  
Register  
IRQ/CP  
Figure 7 - Receiver Timing Diagram  
7
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
LEVEL  
(dBm)  
-25  
0
250  
500  
750  
FREQUENCY (Hz)  
= Reject  
= May Accept  
= Accept  
Figure 8 - Call Progress Response  
EXPLANATION OF EVENTS  
A)  
B)  
C)  
TONE BURSTS DETECTED, TONE DURATION INVALID, RX DATA REGISTER NOT UPDATED.  
TONE #n DETECTED, TONE DURATION VALID, TONE DECODED AND LATCHED IN RX DATA REGISTER.  
END OF TONE #n DETECTED, TONE ABSENT DURATION VALID, INFORMATION IN RX DATA REGISTER  
RETAINED UNTIL NEXT VALID TONE PAIR.  
D)  
E)  
F)  
TONE #n+1 DETECTED, TONE DURATION VALID, TONE DECODED AND LATCHED IN RX DATA REGISTER.  
ACCEPTABLE DROPOUT OF TONE #n+1, TONE ABSENT DURATION INVALID, DATA REMAINS UNCHANGED.  
END OF TONE #n+1 DETECTED, TONE ABSENT DURATION VALID, INFORMATION IN RX DATA REGISTER  
RETAINED UNTIL NEXT VALID TONE PAIR.  
EXPLANATION OF SYMBOLS  
Vin  
DTMF COMPOSITE INPUT SIGNAL.  
ESt  
EARLY STEERING OUTPUT. INDICATES DETECTION OF VALID TONE FREQUENCIES.  
STEERING INPUT/GUARD TIME OUTPUT. DRIVES EXTERNAL RC TIMING CIRCUIT.  
4-BIT DECODED DATA IN RECEIVE DATA REGISTER  
DELAYED STEERING. INDICATES THAT VALID FREQUENCIES HAVE BEEN PRESENT/ABSENT FOR THE  
REQUIRED GUARD TIME THUS CONSTITUTING A VALID SIGNAL. ACTIVE LOW FOR THE DURATION OF A  
VALID DTMF SIGNAL.  
St/GT  
RX0-RX3  
b3  
b2  
INDICATES THAT VALID DATA IS IN THE RECEIVE DATA REGISTER. THE BIT IS CLEARED AFTER THE  
STATUS REGISTER IS READ.  
IRQ/CP  
INTERRUPT IS ACTIVE INDICATING THAT NEW DATA IS IN THE RX DATA REGISTER. THE INTERRUPT IS  
CLEARED AFTER THE STATUS REGISTER IS READ.  
tREC  
tREC  
tID  
tDO  
tDP  
MAXIMUM DTMF SIGNAL DURATION NOT DETECTED AS VALID.  
MINIMUM DTMF SIGNAL DURATION REQUIRED FOR VALID RECOGNITION.  
MINIMUM TIME BETWEEN VALID SEQUENTIAL DTMF SIGNALS.  
MAXIMUM ALLOWABLE DROPOUT DURING VALID DTMF SIGNAL.  
TIME TO DETECT VALID FREQUENCIES PRESENT.  
tDA  
TIME TO DETECT VALID FREQUENCIES ABSENT.  
tGTP  
tGTA  
GUARD TIME, TONE PRESENT.  
GUARD TIME, TONE ABSENT.  
Figure 9 - Description of Timing Events  
8
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
5.0 DTMF Generator  
The DTMF transmitter employed in the MT8889C is capable of generating all sixteen standard DTMF tone pairs  
with low distortion and high accuracy. All frequencies are derived from an external 3.579545 MHz crystal. The  
sinusoidal waveforms for the individual tones are digitally synthesized using row and column programmable  
dividers and switched capacitor D/A converters. The row and column tones are mixed and filtered providing a  
DTMF signal with low total harmonic distortion and high accuracy. To specify a DTMF signal, data conforming to the  
encoding format shown in Table 1 must be written to the transmit Data Register. Note that this is the same as the  
receiver output code. The individual tones which are generated (fLOW and fHIGH) are referred to as Low Group and  
High Group tones. As seen from the table, the low group frequencies are 697, 770, 852 and 941 Hz. The high group  
frequencies are 1209, 1336, 1477 and 1633 Hz. Typically, the high group to low group amplitude ratio (twist) is 2 dB  
to compensate for high group attenuation on long loops.  
The period of each tone consists of 32 equal time segments. The period of a tone is controlled by varying the length  
of these time segments. During write operations to the Transmit Data Register the 4 bit data on the bus is latched  
and converted to 2 of 8 coding for use by the programmable divider circuitry. This code is used to specify a time  
segment length, which will ultimately determine the frequency of the tone. When the divider reaches the appropriate  
count, as determined by the input code, a reset pulse is issued and the counter starts again. The number of time  
segments is fixed at 32, however, by varying the segment length as described above the frequency can also be  
varied. The divider output clocks another counter, which addresses the sinewave lookup ROM.  
The lookup table contains codes which are used by the switched capacitor D/A converter to obtain discrete and  
highly accurate DC voltage levels. Two identical circuits are employed to produce row and column tones, which  
are then mixed using a low noise summing amplifier. The oscillator described needs no “start-up” time as in other  
DTMF generators since the crystal oscillator is running continuously thus providing a high degree of tone burst  
accuracy. A bandwidth limiting filter is incorporated and serves to attenuate distortion products above 8 kHz. It can  
be seen from Figure 6 that the distortion products are very low in amplitude.  
Scaling Information  
10 dB/Div  
Start Frequency = 0 Hz  
Stop Frequency = 3400 Hz  
Marker Frequency = 697 Hz and  
1209 Hz  
Figure 10 - Spectrum Plot  
9
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
6.0 Burst Mode  
In certain telephony applications it is required that DTMF signals being generated are of a specific duration  
determined either by the particular application or by any one of the exchange transmitter specifications currently  
existing. Standard DTMF signal timing can be accomplished by making use of the Burst Mode. The transmitter is  
capable of issuing symmetric bursts/pauses of predetermined duration. This burst/pause duration is 51 ms±1 ms  
which is a standard interval for autodialer and central office applications. After the burst/pause has been issued, the  
appropriate bit is set in the Status Register indicating that the transmitter is ready for more data. The timing  
described above is available when DTMF mode has been selected. However, when CP mode (Call Progress mode)  
is selected, the burst/pause duration is doubled to 102 ms ±2 ms. Note that when CP mode and Burst mode have  
been selected, DTMF tones may be transmitted only and not received. In applications where a non-standard  
burst/pause time is desirable, a software timing loop or external timer can be used to provide the timing pulses  
when the burst mode is disabled by enabling and disabling the transmitter.  
7.0 Single Tone Generation  
A single tone mode is available whereby individual tones from the low group or high group can be generated. This  
mode can be used for DTMF test equipment applications, acknowledgment tone generation and distortion  
measurements. Refer to Control Register B description for details.  
OUTPUT FREQUENCY (Hz)  
ACTIVE  
%ERROR  
INPUT  
SPECIFIED  
697  
ACTUAL  
699.1  
L1  
L2  
L3  
L4  
H1  
H2  
H3  
H4  
+0.30  
-0.49  
-0.54  
+0.74  
+0.57  
-0.32  
-0.35  
+0.73  
770  
766.2  
852  
847.4  
941  
948.0  
1209  
1336  
1477  
1633  
1215.9  
1331.7  
1471.9  
1645.0  
Table 2 - Actual Frequencies Versus Standard Requirements  
10  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
8.0 Distortion Calculations  
The MT8889C is capable of producing precise tone bursts with minimal error in frequency (see Table 2). The  
internal summing amplifier is followed by a first-order lowpass switched capacitor filter to minimize harmonic  
components and intermodulation products. The total harmonic distortion for a single tone can be calculated using  
Equation 1, which is the ratio of the total power of all the extraneous frequencies to the power of the fundamental  
frequency expressed as a percentage.  
V22f + V23f + V24f + .... V2  
nf  
THD (%) = 100  
Vfundamental  
Figure 11 - Equation 1. THD (%) For a Single Tone  
The Fourier components of the tone output correspond to V2f.... Vnf as measured on the output waveform. The total  
harmonic distortion for a dual tone can be calculated using Equation 2. VL and VH correspond to the low group  
amplitude and high group amplitude, respectively and V2IMD is the sum of all the intermodulation components. The  
internal switched-capacitor filter following the D/A converter keeps distortion products down to a very low level as  
shown in Figure 10.  
V22L + V23L + .... V2nL + V2  
+
2H  
V23H + .. V2nH + V2  
IMD  
THD (%) = 100  
V2L + V2  
H
Figure 12 - Equation 2. THD (%) For a Dual Tone  
9.0 DTMF Clock Circuit  
The internal clock circuit is completed with the addition of a standard television colour burst crystal. The crystal  
specification is as follows:  
Frequency:  
3.579545 MHz  
±0.1%  
Frequency Tolerance:  
Resonance Mode:  
Load Capacitance:  
Parallel  
18 pF  
Maximum Series Resistance: 150 ohms  
Maximum Drive Level: 2 mW  
e.g.  
CTS Knights MP036S  
Toyocom TQC-203-A-9S  
A number of MT8889C devices can be connected as shown in Figure 13 such that only one crystal is required.  
Alternatively, the OSC1 inputs on all devices can be driven from a TTL buffer with the OSC2 outputs left  
unconnected.  
11  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
MT8889C  
MT8889C  
MT8889C  
OSC1 OSC2  
OSC1 OSC2  
OSC1 OSC2  
3.579545 MHz  
Figure 13 - Common Crystal Connection  
10.0 Microprocessor Interface  
The MT8889C design incorporates an adaptive interface, which allows it to be connected to various kinds of  
microprocessors. Key functions of this interface include the following:  
Continuous activity on DS/RD is not necessary to update the internal status registers.  
senses whether input timing is that of an Intel or Motorola controller by monitoring the DS (RD), R/W (WR)  
and CS inputs.  
generates equivalent CS signal for internal operation for all processors.  
differentiates between multiplexed and non-multiplexed microprocessor buses. Address and data are  
latched in accordingly.  
compatible with Motorola and Intel processors.  
Figure 19 shows the timing diagram for Motorola microprocessors with separate address and data buses. Members  
of this microprocessor family include 2 MHz versions of the MC6800, MC6802 and MC6809. For the MC6809, the  
chip select (CS) input signal is formed by NANDing the (E+Q) clocks and address decode output. For the MC6800  
and MC6802, CS is formed by NANDing VMA and address decode output. On the falling edge of CS, the internal  
logic senses the state of data strobe (DS). When DS is low, Motorola processor operation is selected.  
Figure 20 shows the timing diagram for the Motorola MC68HC11 (1 MHz) microcontroller. The chip select (CS)  
input is formed by NANDing address strobe (AS) and address decode output. Again, the MT8889C examines the  
state of DS on the falling edge of CS to determine if the micro has a Motorola bus (when DS is low). Additionally, the  
Texas Instruments TMS370CX5X is qualified to have a Motorola interface. Figure 14(a) summarizes connection of  
these Motorola processors to the MT8889C DTMF transceiver.  
Figures 21 and 22 are the timing diagrams for the Intel 8031/8051 (12 MHz) and 8085 (5 MHz) micro-controllers  
with multiplexed address and data buses. The MT8889C latches in the state of RD on the falling edge of CS. When  
RD is high, Intel processor operation is selected. By NANDing the address latch enable (ALE) output with the high-  
byte address (P2) decode output, CS can be generated. Figure 14(b) summarizes the connection of these Intel  
processors to the MT8889C transceiver.  
NOTE: The adaptive micro interface relies on high-to-low transition on CS to recognize the microcontroller interface  
and this pin must not be tied permanently low.  
The adaptive micro interface provides access to five internal registers. The read-only Receive Data Register  
contains the decoded output of the last valid DTMF digit received. Data entered into the write-only Transmit Data  
Register will determine which tone pair is to be generated (see Table 1 for coding details). Transceiver control is  
accomplished with two control registers (see Tables 6 and 7), CRA and CRB, which have the same address. A write  
operation to CRB is executed by first setting the most significant bit (b3) in CRA. The following write operation to the  
same address will then be directed to CRB, and subsequent write cycles will be directed back to CRA. The read-  
only status register indicates the current transceiver state (see Table 8).  
12  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
A software reset must be included at the beginning of all programs to initialize the control registers upon power-up  
or power reset (see Figure 17). Refer to Tables 4-7 for bit descriptions of the two control registers.  
The multiplexed IRQ/CP pin can be programmed to generate an interrupt upon validation of DTMF signals or when  
the transmitter is ready for more data (burst mode only). Alternatively, this pin can be configured to provide a  
square-wave output of the call progress signal. The IRQ/CP pin is an open drain output and requires an external  
pull-up resistor (see Figure 15).  
Motorola  
R/W  
Intel  
WR  
RS0  
RD  
FUNCTION  
Write to Transmit  
Data Register  
0
0
0
1
1
Read from Receive  
Data Register  
0
1
0
Write to Control Register  
Read from Status Register  
1
1
0
1
0
1
1
0
Table 3 - Internal Register Functions  
b3  
b2  
b1  
b0  
RSEL  
IRQ  
CP/DTMF  
TOUT  
Table 4 - CRA Bit Positions  
b3  
b2  
b1  
b0  
C/R  
S/D  
TEST  
BURST  
ENABLE  
Table 5 - CRB Bit Positions  
13  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
MC6800/6802  
MT8889C  
CS  
MT8889  
MC68HC11  
A0-A15  
A8-A15  
AS  
CS  
RS0  
D0-D3  
VMA  
AD0-AD3  
DS  
D0-D3  
RS0  
D0-D3  
DS/RD  
R/W/WR  
DS/RD  
RW  
Φ2  
R/W/WR  
RW  
(a)  
8031/8051  
8080/8085  
MC6809  
MT8889  
MT8889C  
A0-A15  
CS  
A8-A15  
ALE  
CS  
RS0  
Q
E
D0-D3  
RS0  
D0-D3  
D0-D3  
R/W  
P0  
RD  
R/W/WR  
DS/RD  
DS/RD  
R/W/WR  
WR  
(b)  
Figure 14 - a) & b) - MT8889 Interface Connections for Various Intel and Motorola Micros  
BIT  
NAME  
DESCRIPTION  
b0  
TOUT  
Tone Output Control. A logic high enables the tone output; a logic low turns the tone  
output off. This bit controls all transmit tone functions.  
b1  
CP/DTMF Call Progress or DTMF Mode Select. A logic high enables the receive call progress  
mode; a logic low enables DTMF mode. In DTMF mode the device is capable of receiving  
and transmitting DTMF signals. In CP mode a rectangular wave representation of the  
received tone signal will be present on the IRQ/CP output pin if IRQ has been enabled  
(control register A, b2=1). In order to be detected, CP signals must be within the bandwidth  
specified in the AC Electrical Characteristics for Call Progress.  
Note: DTMF signals cannot be detected when CP mode is selected.  
b2  
b3  
IRQ  
Interrupt Enable. A logic high enables the interrupt function; a logic low de-activates the  
interrupt function. When IRQ is enabled and DTMF mode is selected (control register A,  
b1=0), the IRQ/CP output pin will go low when either 1) a valid DTMF signal has been  
received for a valid guard time duration, or 2) the transmitter is ready for more data (burst  
mode only).  
RSEL  
Register Select. A logic high selects control register B for the next write cycle to the  
control register address. After writing to control register B, the following control register  
write cycle will be directed to control register A.  
Table 6 - Control Register A Description  
14  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
BIT  
NAME  
DESCRIPTION  
b0  
BURST  
Burst Mode Select. A logic high de-activates burst mode; a logic low enables burst mode.  
When activated, the digital code representing a DTMF signal (see Table 1) can be written  
to the transmit register, which will result in a transmit DTMF tone burst and pause of equal  
durations (typically 51 msec). Following the pause, the status register will be updated (b1 -  
Transmit Data Register Empty), and an interrupt will occur if the interrupt mode has been  
enabled.  
When CP mode (control register A, b1) is enabled the normal tone burst and pause  
durations are extended from a typical duration of 51 msec to 102 msec.  
When BURST is high (de-activated) the transmit tone burst duration is determined by the  
TOUT bit (control register A, b0).  
b1  
b2  
b3  
TEST  
S/D  
Test Mode Control. A logic high enables the test mode; a logic low de-activates the test  
mode. When TEST is enabled and DTMF mode is selected (control register A, b1=0), the  
signal present on the IRQ/CP pin will be analogous to the state of the DELAYED  
STEERING bit of the status register (see Figure 7, signal b3).  
Single or Dual Tone Generation. A logic high selects the single tone output; a logic low  
selects the dual tone (DTMF) output. The single tone generation function requires further  
selection of either the row or column tones (low or high group) through the C/R bit (control  
register B, b3).  
C/R  
Column or Row Tone Select. A logic high selects a column tone output; a logic low  
selects a row tone output. This function is used in conjunction with the S/D bit (control  
register B, b2).  
Table 7 - Control Register B Description  
BIT  
NAME  
STATUS FLAG SET  
STATUS FLAG CLEARED  
b0  
IRQ  
Interrupt has occurred. Bit one  
(b1) or bit two (b2) is set.  
Interrupt is inactive. Cleared after  
Status Register is read.  
b1  
TRANSMIT DATA  
REGISTER EMPTY  
(BURST MODE ONLY)  
Pause duration has terminated  
and transmitter is ready for new  
data.  
Cleared after Status Register is  
read or when in non-burst mode.  
b2  
b3  
RECEIVE DATA REGISTER  
FULL  
Valid data is in the Receive Data  
Register.  
Cleared after Status Register is  
read.  
DELAYED STEERING  
Set upon the valid detection of  
the absence of a DTMF signal.  
Cleared upon the detection of a  
valid DTMF signal.  
Table 8 - Status Register Description  
15  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
VDD  
MT8880C  
C3  
R4  
VDD  
IN+  
C1  
R1  
C2  
St/GT  
ESt  
DTMF/CP  
INPUT  
IN-  
GS  
R3  
R2  
D3  
VRef  
VSS  
D2  
D1  
OSC1  
OSC2  
TONE  
R/W/WR  
CS  
R5  
D0  
X-tal  
RL  
To µP  
or µC  
IRQ/CP  
DS/RD  
RS0  
DTMF  
OUTPUT  
C4  
Notes:  
R1, R2 = 100 k1%  
R3 = 374 k1%  
R4 = 3.3 k10%  
R5 = 4.7 M10%  
RL = 10 k (min.)  
C1 = 100 nF 5%  
C2 = 100 nF 5%  
C3 = 100 nF 10%*  
C4 = 10 nF 10%  
X-tal = 3.579545 MHz  
* Microprocessor based systems can inject undesirable noise into the supply rails.  
The performance of the MT8889C can be optimized by keeping  
noise on the supply rails to a minimum. The decoupling capacitor (C3) should be  
connected close to the device and ground loops should be avoided.  
Figure 15 - Application Circuit (Single-Ended Input)  
5.0 VDC  
5.0 VDC  
MMD6150 (or  
equivalent)  
2.4 kΩ  
3 kΩ  
TEST POINT  
TEST POINT  
130 pF  
24 kΩ  
100 pF  
MMD7000 (or  
equivalent)  
Test load for D0-D3 pins  
Test load for IRQ/CP pin  
Figure 16 - Test Circuits  
16  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
INITIALIZATION PROCEDURE  
A software reset must be included at the beginning of all programs to initialize the control registers after power  
up. The initialization procedure should be implemented 100ms after power up.  
Description:  
Motorola  
Intel  
Data  
b1  
RS0  
R/W  
WR RD  
b3  
b2  
b0  
1) Read Status Register  
2) Write to Control Register  
3) Write to Control Register  
4) Write to Control Register  
5) Write to Control Register  
6) Read Status Register  
1
1
1
1
1
1
1
0
0
0
0
1
1
0
0
0
0
1
0
1
1
1
1
0
X
0
0
1
0
X
X
0
0
0
0
X
X
0
0
0
0
X
X
0
0
0
0
X
TYPICAL CONTROL SEQUENCE FOR BURST MODE APPLICATIONS  
Transmit DTMF tones of 50 ms burst/50 ms pause and Receive DTMF Tones.  
Sequence:  
RS0  
1
R/W  
0
WR  
0
RD  
1
b3  
b2  
1
b1  
0
b0  
1
1) Write to Control Register A  
1
(tone out, DTMF, IRQ, Select Control Register B)  
2) Write to Control Register B  
(burst mode)  
1
0
0
0
1
1
0
0
0
1
0
1
0
1
3) Write to Transmit Data Register  
(send a digit 7)  
0
0
4) Wait for an Interrupt or Poll Status Register  
5) Read the Status Register  
1
1
1
0
1
X
0
X
1
X
0
X
1
-if bit 1 is set, the Tx is ready for the next tone, in which case...  
Write to Transmit Register  
(send a digit 5)  
0
0
0
-if bit 2 is set, a DTMF tone has been received, in which case....  
Read the Receive Data Register  
0
1
1
0
X
X
X
X
-if both bits are set...  
Read the Receive Data Register  
Write to Transmit Data Register  
0
0
1
0
1
0
0
1
X
0
X
1
X
0
X
1
NOTE: IN THE TX BURST MODE, STATUS REGISTER BIT 1 WILL NOT BE SET UNTIL 100 ms (±2 ms) AFTER THE DATA IS  
WRITTEN TO THE TX DATA REGISTER. IN EXTENDED BURST MODE THIS TIME WILL BE DOUBLED TO 200 ms (± 4 ms)  
Figure 17 - Application Notes  
17  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
Absolute Maximum Ratings*  
Parameter  
Power supply voltage VDD-VSS  
Symbol  
Min.  
Max.  
Units  
1
2
3
4
5
VDD  
VI  
6
V
Voltage on any pin  
VSS-0.3  
-65  
VDD+0.3  
10  
V
Current at any pin (Except VDD and VSS  
)
mA  
°C  
Storage temperature  
TST  
PD  
+150  
1000  
Package power dissipation  
mW  
* Exceeding these values may cause permanent damage. Functional operation under these conditions is not implied.  
Recommended Operating Conditions - Voltages are with respect to ground (V ) unless otherwise stated.  
SS  
Parameter  
Sym.  
Min.  
Typ.‡  
Max.  
Units  
Test Conditions  
1
2
3
Positive power supply  
Operating temperature  
Crystal clock frequency  
VDD  
TO  
4.75  
-40  
5.00  
5.25  
+85  
V
°C  
fCLK  
3.575965 3.579545 3.583124  
MHz  
‡ Typical figures are at 25 °C and for design aid only: not guaranteed and not subject to production testing.  
DC Electrical Characteristics- V =0 V.  
SS  
Characteristics  
Sym.  
Min. Typ.Max. Units  
Test Conditions  
1
2
3
4
Operating supply voltage  
Operating supply current  
Power consumption  
VDD  
IDD  
4.75  
5.0  
7.0  
5.25  
11  
V
mA  
mW  
V
S
U
P
PC  
57.8  
High level input voltage  
(OSC1)  
VIHO  
3.5  
Note 9*  
I
N
P
U
T
S
5
Low level input voltage  
(OSC1)  
VILO  
VTSt  
VOLO  
VOHO  
1.5  
2.5  
0.1  
V
V
V
V
Note 9*  
6
7
Steering threshold voltage  
2.2  
2.3  
VDD=5V  
Low level output voltage  
(OSC2)  
No load  
Note 9*  
O
U
T
P
U
T
8
9
High level output voltage  
(OSC2)  
No load  
Note 9*  
4.9  
2.4  
Output leakage current  
(IRQ)  
IOZ  
VRef  
ROR  
VIL  
1
10  
µA  
V
VOH=2.4 V  
S
10  
11  
12  
13  
14  
V
Ref output voltage  
2.5  
1.3  
2.6  
No load, VDD=5V  
VRef output resistance  
Low level input voltage  
High level input voltage  
Input leakage current  
kΩ  
V
D
i
g
i
0.8  
10  
VIH  
IIZ  
2.0  
V
µA  
VIN=VSS to VDD  
t
a
l
15  
16  
17  
18  
Source current  
Sink current  
IOH  
IOL  
IOH  
IOL  
-1.4  
2.0  
-0.5  
2
-6.6  
4.0  
-3.0  
4
mA VOH=2.4V  
mA VOL=0.4V  
mA VOH=4.6V  
mA VOL=0.4V  
Data  
Bus  
ESt  
and  
St/GT  
Source current  
Sink current  
18  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
DC Electrical Characteristics(continued)- V =0 V.  
SS  
Characteristics  
Sink current  
Sym.  
Min. Typ.Max. Units  
16 mA VOL=0.4V  
Test Conditions  
IRQ/  
CP  
19  
IOL  
4
† Characteristics are over recommended operating conditions unless otherwise stated.  
‡ Typical figures are at 25 °C, VDD =5V and for design aid only: not guaranteed and not subject to production testing.  
* See “Notes” following AC Electrical Characteristics Tables.  
Electrical Characteristics Gain Setting Amplifier - Voltages are with respect to ground (VSS) unless otherwise stated, VSS= 0V.  
Characteristics  
Sym.  
Min.  
Typ.  
Max.  
Units  
Test Conditions  
1
2
3
4
5
6
7
8
Input leakage current  
Input resistance  
IIN  
RIN  
100  
nA  
MΩ  
mV  
dB  
VSS VIN VDD  
10  
Input offset voltage  
VOS  
25  
Power supply rejection  
Common mode rejection  
DC open loop voltage gain  
Unity gain bandwidth  
Output voltage swing  
PSRR  
CMRR  
AVOL  
BW  
50  
40  
1 kHz  
dB  
40  
dB  
CL = 20p  
CL = 20p  
1.0  
0.5  
MHz  
V
VO  
VDD-0.5  
100  
RL 100 kto VSS  
9
Allowable capacitive load (GS)  
CL  
RL  
pF  
kΩ  
V
PM>40°  
VO = 4Vpp  
RL = 50kΩ  
10 Allowable resistive load (GS)  
11 Common mode range  
50  
VCM  
1.0  
VDD-1.0  
Figures are for design aid only: not guaranteed and not subject to production testing.  
Characteristics are over recommended operating conditions unless otherwise stated.  
MT8889C AC Electrical Characteristics- Voltages are with respect to ground (VSS) unless otherwise stated.  
Characteristics  
Sym.  
Min.  
Typ.Max.  
Units  
Notes*  
1,2,3,5,6  
1,2,3,5,6  
Valid input signal levels  
(each tone of composite  
signal)  
-29  
+1  
dBm  
R
X
1
27.5  
869  
mVRMS  
† Characteristics are over recommended operating conditions (unless otherwise stated) using the test circuit shown in Figure 15.  
AC Electrical Characteristics- Voltages are with respect to ground (VSS) unless otherwise stated. fC=3.579545 MHz  
Characteristics  
Sym.  
Min.  
Typ.‡  
Max.  
Units  
Notes*  
1
2
3
4
5
6
7
Positive twist accept  
Negative twist accept  
Freq. deviation accept  
Freq. deviation reject  
Third tone tolerance  
Noise tolerance  
8
8
dB  
dB  
2,3,6,9  
2,3,6,9  
2,3,5  
±1.5%± 2Hz  
±3.5%  
R
X
2,3,5  
-16  
-12  
22  
dB  
dB  
dB  
2,3,4,5,9,10  
2,3,4,5,7,9,10  
2,3,4,5,8,9  
Dial tone tolerance  
† Characteristics are over recommended operating conditions unless otherwise stated.  
‡ Typical figures are at 25°C, VDD = 5V, and for design aid only: not guaranteed and not subject to production testing.  
* *See “Notes” following AC Electrical Characteristics Tables.  
19  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
AC Electrical Characteristics- Call Progress - Voltages are with respect to ground (VSS), unless otherwise stated.  
Characteristics  
Accept Bandwidth  
Sym.  
Min.  
Typ.‡  
Max. Units  
Conditions  
@ -25 dBm,  
1
fA  
310  
500  
Hz  
Note 9  
2
3
4
Lower freq. (REJECT)  
Upper freq. (REJECT)  
fLR  
fHR  
290  
540  
Hz  
Hz  
@ -25 dBm  
@ -25 dBm  
Call progress tone detect level (total  
power)  
-30  
dBm  
† Characteristics are over recommended operating conditions unless otherwise stated  
‡ Typical figures are at 25°C, VDD=5V, and for design aid only: not guaranteed and not subject to production testing  
AC Electrical Characteristics- DTMF Reception - Typical DTMF tone accept and reject requirements. Actual values are user  
selectable as per Figures 5, 6 and 7.  
Characteristics  
Sym.  
Min.  
Typ.Max. Units  
Conditions  
1
2
3
4
Minimum tone accept duration  
Maximum tone reject duration  
Minimum interdigit pause duration  
Maximum tone drop-out duration  
tREC  
tREC  
tID  
40  
20  
40  
20  
ms  
ms  
ms  
ms  
tDO  
† Characteristics are over recommended operating conditions unless otherwise stated  
‡ Typical figures are at 25°C, VDD=5V, and for design aid only: not guaranteed and not subject to production testing  
AC Electrical Characteristics- Voltages are with respect to ground (VSS), unless otherwise stated.  
Characteristics  
Sym.  
Min.  
Typ.‡  
Max.  
Units  
Conditions  
T
O
N
E
1
2
3
4
Tone present detect time  
Tone absent detect time  
Delay St to b3  
tDP  
tDA  
tPStb3  
tPStRX  
3
11  
4
14  
ms Note 11  
ms Note 11  
0.5  
8.5  
13  
8
µs  
µs  
See Figure 7  
See Figure 7  
I
N
Delay St to RX0-RX3  
5
6
Tone burst duration  
tBST  
tPS  
tBSTE  
tPSE  
50  
50  
52  
52  
ms DTMF mode  
ms DTMF mode  
ms Call Progress mode  
ms Call Progress mode  
dBm RL=10kΩ  
Tone pause duration  
7
Tone burst duration (extended)  
Tone pause duration (extended)  
High group output level  
Low group output level  
Pre-emphasis  
100  
100  
-6.1  
-8.1  
0
104  
104  
-2.1  
-4.1  
3
T
O
N
E
8
9
VHOUT  
VLOUT  
dBP  
10  
11  
12  
13  
14  
15  
dBm RL=10kΩ  
O
U
T
2
dB  
dB  
RL=10kΩ  
Output distortion (Single Tone)  
THD  
-35  
25 kHz Bandwidth  
RL=10kΩ  
Frequency deviation  
fD  
±0.7  
±1.5  
%
fC=3.579545 MHz  
Output load resistance  
RLT  
10  
50  
kΩ  
20  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
AC Electrical Characteristics(continued) - Voltages are with respect to ground (VSS), unless otherwise stated.  
Characteristics  
Sym.  
Min.  
Typ.‡  
Max.  
Units  
Conditions  
16  
17  
18  
19  
Crystal/clock frequency  
Clock input rise and fall time  
Clock input duty cycle  
fC  
3.5759 3.5795 3.5831 MHz  
X
T
A
L
tCLRF  
DCCL  
CLO  
110  
60  
ns  
%
Ext. clock  
Ext. clock  
40  
50  
Capacitive load (OSC2)  
30  
pF  
† Timing is over recommended temperature & power supply voltages.  
‡ Typical figures are at 25°C and for design aid only: not guaranteed and not subject to production testing.  
AC Electrical Characteristics- MPU Interface - Voltages are with respect to ground (VSS), unless otherwise stated.  
Characteristics  
Sym.  
Min.  
Typ.Max.  
Units  
Conditions  
Figure 18  
1
2
3
4
5
6
7
8
9
DS/RD/WR clock frequency  
DS/RD/WR cycle period  
DS/RD/WR low pulse width  
DS/RD/WR high pulse width  
DS/RD/WR rise and fall time  
R/W setup time  
fCYC  
tCYC  
tCL  
4.0  
MHz  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
ns  
pF  
pF  
250  
Figure 18  
150  
Figure 18  
tCH  
100  
20  
Figure 18  
tR,tF  
tRWS  
tRWH  
tAS  
Figure 18  
23  
20  
0
Figures 19 & 20  
Figures 19 & 20  
Figures 19 - 22  
Figures 19 - 22  
Figures 19 - 22  
Figures 19 - 22  
Figures 19 - 22  
Figures 19 - 22  
Figures 19 - 22  
Figures 19 - 22  
R/W hold time  
Address setup time (RS0)  
Address hold time (RS0)  
tAH  
40  
22  
20  
10 Data hold time (read)  
tDHR  
tDDR  
tDSW  
tDHW  
tCSS  
tCSH  
CIN  
11 DS/RD to valid data delay (read)  
12 Data setup time (write)  
13 Data hold time (write)  
100  
45  
10  
45  
40  
14 Chip select setup time  
35  
15 Chip select hold time  
16 Input Capacitance (data bus)  
17 Output Capacitance (IRQ/CP)  
5
5
COUT  
† Characteristics are over recommended operating conditions unless otherwise stated  
‡ Typical figures are at 25°C, VDD=5V, and for design aid only: not guaranteed and not subject to production testing  
NOTES:  
1. dBm=decibels above or below a reference power of 1 mW into a 600 ohm load.  
2.  
Digit sequence consists of all 16 DTMF tones.  
3. Tone duration=40 ms. Tone pause=40 ms.  
4. Nominal DTMF frequencies are used.  
5. Both tones in the composite signal have an equal amplitude.  
6. The tone pair is deviated by ± 1.5%±2 Hz.  
7. Bandwidth limited (3 kHz) Gaussian noise.  
8. The precise dial tone frequencies are 350 and 440 Hz (±2%).  
9. Guaranteed by design and characterization. Not subject to production testing.  
10. Referenced to the lowest amplitude tone in the DTMF signal.  
11. For guard time calculation purposes.  
21  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
tCYC  
tR  
tF  
tCH  
tCL  
DS/RD/WR  
Figure 18 - DS/RD/WR Clock Pulse  
tRWH  
tRWS  
DS  
Q clk*  
A0-A15  
(RS0)  
16 bytes of Addr  
R/W(read)  
tDDR  
tDHR  
Read Data  
(D3-D0)  
R/W (write)  
tDSW  
tDHW  
Write data  
(D3-D0)  
tCSS  
tCSH  
tAH  
tAS  
CS = (E + Q).Addr [MC6809]  
tAH  
CS = VMA.Addr [MC6800, MC6802]  
*microprocessor pin  
tAS  
tCSS  
tCSH  
Figure 19 - MC6800/MC6802/MC6809 Timing Diagram  
Note: tDSW is from data to DS falling edge; tCSH is from DS rising edge to CS rising edge  
22  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
tRWS  
DS  
tRWH  
R/W  
tDHR  
tDDR  
tAS  
Read  
AD3-AD0  
(RS0, D0-D3)  
Addr  
Data  
Write  
AD3-AD0  
(RS0-D0-D3)  
Data  
tDHW  
Addr  
tDSW  
tAH  
tCSH  
Addr *  
non-mux  
High Byte of Addr  
AS *  
CS = AS.Addr  
tCSS  
* microprocessor pins  
Figure 20 - MC68HC11 Bus Timing (with multiplexed address and data buses)  
tCSS  
ALE*  
RD  
tDHR  
tAS  
tDDR  
tAH  
A0-A7  
P0*  
(RS0,  
D0-D3)  
Data  
P2 *  
(Addr)  
A8-A15 Address  
tCSH  
CS = ALE.Addr  
* microprocessor pins  
Figure 21 - 8031/8051/8085 Read Timing Diagram  
23  
Zarlink Semiconductor Inc.  
MT8889C  
Data Sheet  
ALE*  
WR  
tCSS  
tDSW  
Data  
tAS  
tAH  
A0-A7  
tDHW  
P0*  
(RS0,  
D0-D3)  
P2 *  
(Addr)  
A8-A15 Address  
tCSH  
CS = ALE.Addr  
* microprocessor pins  
Figure 22 - 8031/8051/8085 Write Timing Diagram  
24  
Zarlink Semiconductor Inc.  

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