AT43312 [ATMEL]
Self- and Bus- Powered USB Hub Controller; 自营和总线供电的USB集线器控制器
| 型号： | AT43312 |
| 厂家： | 
ATMEL |
| 描述： | Self- and Bus- Powered USB Hub Controller |
| 文件： | 总21页 (文件大小：160K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Features
• Full compliance with USB spec Rev 1.0
• Four downstream ports
• Full speed and low speed data transfers
• Self-Powered or Bus-Powered modes of operation
• Per port overcurrent monitoring
• Individual port power switch control
• USB connection status indicators
Description
Self- and Bus-
Powered USB
Hub Controller
The AT43312 is a 5 port USB hub chip supporting one upstream and four downstream
ports. The AT43312 connects to an upstream hub or Host/Root Hub via Port0 and the
other ports connect to external downstream USB devices. The hub re-transmits the
USB differential signal between Port0 and Ports[1:4] in both directions. A USB hub
with the AT43312 can operate as a bus-powered or self-powered through chip’s
power mode configuration pin. The AT43312 is pin- and function-compatible with the
AT43311 and can be used as a replacement for the AT43310 with one pin modifica-
tion.
AT43312
The AT43312 supports the 12 Mb/s full-speed as well as 1.5 Mb/s slow-speed USB
transactions. To reduce EMI, the AT43312’s oscillator frequency is 6 MHz even
though some internal circuitry operates at 48 MHz.
Pin Configurations
SOIC/DIP
PWR2
PWR3
PWR4
VCC5
GND
1
2
3
4
5
6
7
8
9
32 PWR1
31 DP4
30 DM4
29 DP3
28 DM3
27 GND
26 DP2
25 DM2
24 VCC3
23 DP1
22 DM1
21 DP0
20 DM0
19 STAT1
18 STAT2
17 STAT3
OSC1
OSC2
LFT
VCCA
OVL4 10
OVL3 11
OVL2 12
OVL1 13
VREF 14
BUS/SELF 15
STAT4 16
Rev. 1002A-A–01/98
Block Diagram
Upstream port
Port0
HUB
SERIAL INTERFACE
ENGINE
HUB
CONTROLLER
REPEATER
ENDPOINT 0
ENDPOINT 1
PORT1
PORT2
PORT3
PORT4
To downstream
devices
Note:
This document assumes that the reader is familiar with the Universal Serial Bus and therefore only describes the unique fea-
tures of the AT43312 chip. For detailed information about the USB and its operation, the reader should refer to the Universal
Serial Bus Specification Version 1.0, January 19, 1996.
Figure 1. Device Pins
DP4
DM4
LFT
OSC1
PSC2
OSC
&
OVL4
PWR4
STAT4
PORT4
PLL
DP3
DM3
SERIAL
INTERFACE
ENGINE
OVL3
PWR3
STAT3
PORT3
PORT2
DP0
DM0
DP2
DM2
HUB
OVL2
PWR2
STAT2
REPEATER
BUS/SELF
VREF
VCC3
VCC5
VCCA
GND
DP1
DM1
HUB
PORT4
OVL1
PWR1
STAT1
CONTROLLER
AT43312
2
AT43312
Pin Description
Pin Description Pin Type Description
OSC1
OSC2
LFT
I
O
I
Oscillator Input. Input to the inverting 6 MHz oscillator amplifier.
Oscillator Output. Output of the inverting oscillator amplifier.
PLL Filter. For proper operation of the PLL, this pin should be connected through a 2.2 nF capacitor in
parallel with a 100 Ω resistor in series with a 10 nF capacitor to ground (GND)
BUS/SELF
VREF
I
I
Hub Power Mode. Input signal that sets the bus or self-powered mode operation. A high on this pin
enables the bus-powered mode, a low the self-powered mode.
Reference Voltage. This is an input pin that should be connected to an external voltage source. VREF
is used internally as the reference voltage by the overload protection circuit to decide whether there is
a problem with a port’s power.
DP0
B
Upstream Plus USB I/O. This pin should be connected to VCC through an external 1.5 KΩ pullup
resistor. DP0 and DM0 form the differential signal pin pairs connected to the Host Controller or an
upstream Hub.
DM0
B
B
Upstream Minus USB I/O
DP[1:4]
Port Plus USB I/O. This pin should be connected to VSS through an external 15 KΩ resistor. DP[1:4]
and DM[1:4] are the differential signal pin pairs to connect downstream USB devices.
DM[1:4]
B
I
Port Minus USB I/O. This pin should be connected to VSS through an external 15 KΩ resistor.
OVC[1:4]
Overcurrent. This is the input signal used to indicate to the AT43312 that an overcurrent is detected at
the port. If OVC is asserted, AT43312 will assert the PWRx pin and report the status to the USB Host.
PWR[1:4]
STAT[1:4]
OD
O
Power Switch. This is an output signal used to enable or disable the external voltage regulator
supplying power to a port. PWRx is de-asserted when a power supply problem is detected at OVCx.
Connect Status. This is an output pin indicating that a port is properly connected. STATx is asserted
when the port is enabled.
VCC3
VCC5
VCCA
GND
V
V
V
V
3.3V Power Supply
5V Power Supply
5V Analog Power Supply
Ground
Note:
Signals with a # are active low.
3
Functional Description
The Atmel AT43312 is a USB hub controller for use in a
standalone hub, as well as an add-on hub for an existing
non-USB peripheral such as a PC display monitor or key-
board. In addition to supporting the standard USB hub
functionality, the AT43312 has additional features to
enhance the user friendliness of the hub.
and will disable them at the end of an EOP. Packets out of
Port0 are always transmitted using the full-speed drivers.
All the AT43312 ports independently drive and monitor
their DP and DM pins so that they are able to detect and
generate the ‘J’, ‘K’, and SE0 bus signaling states. Each
hub port has single-ended and differential receivers on its
DP and DM lines. The ports I/O buffers comply to the volt-
age levels and drive requirements as specified in the USB
Specifications Rev 1.0.
USB Ports
The AT43312’s downstream ports are standard USB ports.
That is, their functionality complies to the USB specification
and any USB compliant device can be attached to these
ports without any other circuitry or modification. Each port
has a port connectivity status pin.
The Hub Repeater implements a frame timer which is timed
by the 12MHz USB clock and gets reset every time a SOF
token is received from the Host.
Dp And Dm Configuration
Serial Interface Engine
To match the full-speed cable impedance, 27 Ω series
resistors must be connected between each port’s DM and
DP pins to their corresponding USB connector. In addition,
15 KΩ pull-down resistors are required at each down-
stream port’s DM and DP pins. Port0 is a full-speed port
and requires a 1.5 KΩ pull-up resistor to the 3.3V power
supply. This power supply must be derived from the bus
supplied power.
The Serial Interface Engine handles the USB communica-
tion protocol. It performs the USB clock/data separation,
the NRZI data encoding/decoding, bit stuffing, CRC gener-
ation and checking, USB packet ID decoding and genera-
tion, and data serialization and de-serialization. The on-
chip phase locked loop generates the high-frequency clock
for the clock/data separation circuit.
Power Management
Port Status Pin
A hub is a high-powered device and is allowed to draw up
to 500 mA of current from the host or upstream hub. The
AT43312 chip itself and its external hub circuitry consume
less than 100 mA. The AT43312’s power management
logic work with external devices to detect overcurrent and
control power to the ports.
The STATx pins are signals that are not required by the
USB specification. Their function is to allow the hub to pro-
vide feedback to the user whenever a device is properly
connected to the port. A LED and series resistor connected
to STAx can be used to provide a visual feedback.
The default state of STATx is inactive. After a port is
enabled, AT43312 will assert the port’s STATx. Any condi-
tion that causes the port to be disabled inactivates STATx.
Overcurrent sensing is on a per port basis and is achieved
through the OVCx pins. Each of the OVCx pin is the plus
input of an analog comparator whose other input is con-
nected to a reference voltage source, VREF which is com-
mon to all four ports. Whenever the voltage at OVCx is less
than VREF, the AT43312 treats it as an overcurrent condi-
tion. This could be caused by an overload, or even a short
circuit, and causes the AT43312 to set the port’s
PORT_OVER_CURRENT status bit and its
C_PORT_OVER_CURRENT status change bit. At the
same time, power to the offending port is shut off.
Hub Repeater
The Hub Repeater is responsible for port connectivity setup
and tear-down. It also supports exception handling such as
bus fault detection and recovery, and connect/disconnect
detection. Port0 is the root port and is connected to the root
hub or an upstream hub. When a packet is received at
Port0, the AT43312 propagates it to all of the enabled
downstream ports. Conversely, a packet from a down-
stream port is transmitted from Port0.
An external device is needed to perform the actual switch-
ing of the ports’ power under control of the AT43312. The
signal to control the external switches are the PWRx pins
which are open drain signals and require external pull-up
resistors of 10 KΩ. Any type of suitable switch or device is
acceptable. However, it should have a low-voltage drop
across it even when the port absorbs full power. In its sim-
plest form, this switch can be a P-channel MOSFET. The
advantages of using a MOSFET switch is its very low volt-
age drop and low cost.
The AT43312 supports downstream port data signaling at
both 1.5 Mb/s and 12 Mb/s. Devices attached to the down-
stream ports are determined to be either full-speed or low-
speed depending on which data line (DP or DM) is pulled
high. If a port is enumerated as low speed, its output buff-
ers operate at a slew rate of 75-300 ns, and the AT43312
will not propagate any traffic to that port unless it is pref-
aced with a preamble PID. Low-speed data following the
preamble PID is propagated to both low and full-speed
devices. The AT43312 will enable low-speed drivers within
four full-speed bit times of the last bit of a preamble PID,
Each one of the AT43312’s port has its own power control
pin
which
is
asserted
only
when
a
Set_Port_Feature[PORT-POWER] request is received
AT43312
4
AT43312
from the host. PWRx is de-asserted under the following
conditions:
tion of the power switch and PC board layout is required to
meet the specifications. When using a MOSFET switch, its
resistance must be 140 MΩ or less, under worst case con-
ditions. A suitable MOSFET switch for an AT43312 based
hub is a P-channel enhancement mode MOSFET. The
input of the PMOS switch is connected to the local 5V
power supply while the output is connected to the port
power line, as well as the port’s OVCx pin. An overcurrent
condition increases the voltage drop across the MOSFET.
If this voltage drops to less than the voltage at VREF, the
AT43312 voltage reference pin, the AT43312 interpretes
this as an overcurrent condition. The AT43312 removes the
power from that port by de-activating the port’s PWRx pin
and reports the condition to the Host.
1. Power up
2. Reset and initialization
3. Overcurrent condition
Self-powered Mode
In the self-powered mode, power to the downstream ports
must be supplied by an external power supply. This power
supply must be capable of supplying 500 mA per port.
The USB specifications require that the voltage drop at the
power switch, and board traces be no more than 100 mV. A
good conservative maximum drop at the power switch itself
should be no more than 750 mV. Careful design and selec-
Figure 2. Self-Powered Hub Power Supply
3V REG
IN
OUT
BUS_POWER
GND
GND
POWER SUPPLY
VCC5
GND
VCC3
5V OUT
GND
R1
R2
VREF AT43312
PWR OVC DM DP
DP
DM
To
MOSFET P
downstream
device
PORT_POWER
GND
Bus-powered Mode
In the bus-powered mode, all the power for the hub itself as
well as the downstream ports are supplied by the root hub
or upstream hub through the USB. Only 100 mA is avail-
able for each of the hub’s downstream devices and there-
fore only low power devices are supported.
The diagrams of Figures 2 and 3 show examples of the
power supply and management connections for a typical
AT43312 port in the self-powered mode and bus-powered
mode.
The power switch and overcurrent protection work exactly
like the self-powered mode, except that the allowable
switch resistance is higher: 700 MΩ or less under the
worst-case condition.
5
Figure 3. Bus-Powered Hub Power Supply
3V REG
IN
OUT
BUS_POWER
GND
GND
VCC5
GND
VCC3
R1
R2
VREF AT43312
Y
PWR OVC DM DP
DP
DM
To
MOSFET P
downstream
device
PORT_POWER
GND
Hub Controller
The Hub Controller of the AT43312 provides the mecha-
nism for the Host to enumerate the Hub, and the AT43312
to provide the Host with its configuration information. It also
provides a mechanism for the Host to monitor and control
the downstream ports. Power is applied, on a per port
basis, by the Hub Controller upon receiving a command,
Set_Port_Feature[PORT_POWER], from the Host. The
AT43312 itself must be configured first by the Host before
the Hub Controller can apply power to external devices.
The Hub Controller contains two endpoints, Endpoint0 and
Endpoint1, and maintains a status register, Controller Sta-
tus Register, which reflects the AT43312’s current settings.
At power up, all bits in this register will be set to 0’s.
Control Status Register
Bit Function
Value Description
Set to 0 or 1 by a Set_Configuration Request
Hub is not currently configured
0
Hub configuration status
0
1
Hub is currently configured
1
Hub remote wakeup status
Set to 0 or 1 by ClearFeature or SetFeature request. Default value is 0.
Hub is currently not enabled to request remote wakeup
Hub is currently enabled to request remote wakeup
0
1
2
3
Endpoint0 STALL status
Endpoint1 STALL status
0
1
Endpoint0 is not stalled
Endpoint0 is stalled
0
1
Endpoint1 is not stalled
Endpoint1 is stalled
AT43312
6
AT43312
Endpoint0
Endpoint1
Endpoint0 is the AT43312’s default endpoint used for enu-
meration of the Hub and exchange of configuration infor-
mation and requests between the Host and the AT43312.
Endpoint0 supports control transfers.
Endpoint1, an interrupt endpoint, is used by the Hub Con-
troller to send status change information to the Host.
The Hub Controller samples the changes at the end of
every frame at time marker EOF2 in preparation for a
potential data transfer in the subsequent frame. The sam-
pled information is stored in a byte-wide register, the Status
Change Register, using a bitmap scheme.
The Hub Controller supports the following descriptors:
Device Descriptor, Configuration Descriptor, Interface
Descriptor, Endpoint Descriptor, and Hub Descriptor.
These Descriptors are described in detail on page 9
through page 16 of this document. Standard USB Device
Requests and class-specific Hub Requests are also sup-
ported through Endpoint0. There is no endpoint descriptor
for Endpoint0.
Each bit in the Status Change Register corresponds to one
port as shown below:
Status Change Register
Bit Function
Value Meaning
0
1
2
3
4
Hub status change
0
1
No change in status
Change in status detected
Port1 status change
Port2 status change
Port3 status change
Port4 status change
0
1
No change in status
Change in status detected
0
1
No change in status
Change in status detected
0
1
No change in status
Change in status detected
0
1
No change in status
Change in status detected
5-7 Reserved
000
Default values
An IN Token packet from the Host to Endpoint1 indicates a
request for port change status. If the Hub has not detected
any change on its ports, nor any changes in itself, then all
bits in this register will be 0 and the Hub Controller will
return a NAK to requests on Endpoint1. If any of bits 0-4 is
1, the Hub Controller will transfer the whole byte. The Hub
Controller will continue to report a status change when
polled until that particular change has been removed by a
Clear_Port_Feature request from the Host. No status
change will be reported by Endpoint1 until the AT43312
has been enumerated and configured by the Host via
Endpoint0.
7
Oscillator and Phase-Locked-Loop
All the clock signals required to run the AT43311 are
derived from an on-chip oscillator. To reduce EMI and
power dissipation in the system, the oscillator is designed
to operate with a 6 MHz crystal. An on-chip PLL generates
the high-frequency for the clock/data separator of the Serial
Interface Engine. In the suspended state, the oscillator cir-
cuitry is turned off. To assure quick startup, a crystal with a
high Q, or low ESR, should be used. To meet the USB hub
frequency accuracy and stability requirements for hubs, the
crystal should have an accuracy and stability of better than
500 PPM. Even though the oscillator circuit would work
with a ceramic resonator, its use is not recommended
because a resonator would not have the frequency accu-
racy and stability.
pin to maintain good noise margins at the low switching
level.
Figure 4. Oscillator and PLL Connections
U1
C1
22pF
OSC1
C2
Y1
22pF
6.000 MHz
AT43312
OSC2
LFT
R1
R2
100
100
C4
2nF
C3
10nF
A 6 MHz series resonance quartz crystal with a load capac-
itance of approximately 10 pF is recommended. If the crys-
tal recommended load capacitor is larger, external capaci-
tors added to pins OSC1 and OSC2 are recommend. The
values for these capacitors depends on the crystal and the
layout of the board, but a starting value of 22 pF at OSC1
and OSC2 should work fine in most cases. If the crystal
used cannot tolerate the drive levels of the oscillator, a
series resistor between OSC2 and the crystal pin is recom-
mended.
For proper operation of the PLL, an external RC filter con-
sisting of a series RC network of 100 Ω and 10 nF in paral-
lel with a 2 nF capacitor must be connected from the LFT
pin to VSS.
To provide the best operating condition for the AT43312,
careful consideration of the power supply connections are
recommended. Use short, low impedance connections to
all power supply lines: VCC, VCCA and VSS. Use sufficient
decoupling capacitors to reduce noise: 0.1 µF decoupling
high-quality capacitors, soldered as close as possible to
the package pins are recommended.
The clock can also be externally sourced. In this case, con-
nect the clock source to the OSC1 pin, while leaving OSC2
pin floating. The switching level at the OSC1 pin can be as
low as 0.47V (see “Oscillator Signals: OSC1, OSC2” table
on page 18) and a CMOS device is required to drive this
AT43312
8
AT43312
Descriptors
The Hub Controller supports the following standard USB
descriptors: Device, Configuration, Interface, and Endpoint
Descriptors, as well as the class-specific Hub Descriptor.
All the obligatory Standard Requests and Hub Class-Spe-
cific Requests are supported by the AT43312’s Hub Con-
troller. The description is given for the self-powered mode
of operation. Unique parameters for the bus-powered mode
is given in case of differences.
Device Descriptor
The Device Descriptor provides general information about the AT43312 Hub.
Offset Field
Description
Size (bytes) Value
0
1
2
bLength
Define size of this descriptor = 18 bytes
Device descriptor type
1
1
2
0x12
0x01
bDescriptorType
bcdUSB
USB Spec. Release Number = Rev 1.0
0x00
0x01
4
5
6
7
8
bDeviceClass
bDeviceSubClass
bDeviceProtocol
wMaxPacketSize0
idVendor
Class code = HUB_CLASSCODE = 09
Subclass code
1
1
1
1
2
0x09
0x00
0x00
0x08
Protocol code
Max. packet size for Endpoint0 = 8 bytes
Vendor ID = Atmel Corporation
0xEB
0x03
10
12
idProduct
bcdDevice
Product ID = AT43312
2
2
0x12
0x33
Device release number
0XZZ
0XYY
Example :
Revision A0 : yy = 0x01, zz = 0x00
Revision B1 : yy = 0x02, zz = 0x01
14
15
16
17
iManufacturer
iProduct
Index of string descriptor describing manufacturer = not supported
Index of string descriptor describing product = not supported
Index of string descriptor describing device's serial no. = not supported
1
1
1
1
0x00
0x00
0x00
0x01
iSerialNumber
bNumConfigurations Number of possible configurations = 1
9
Configuration Descriptor
This Configuration Descriptor provides information about AT43312’s configuration.
Offset Field
Description
Size (bytes) Value
0
1
2
bLength
Define size of this descriptor = 9 bytes
Descriptor type = Configuration
1
1
2
0x09
0x02
bDescriptorType
wTotalLength
Total length of data returned for this configuration. Consists of the
combined length of configuration, interface, endpoint and hub descriptors
= 34 bytes
0x22
0x00
4
5
bNumInterface
Number of interfaces supported by this configuration
1
1
0x01
0x01
bConfiguration
Value
Argument value for this configuration to be used by Set Configuration
command
6
7
iConfiguration
bmAttributes
Index of string descriptor describing this configuration (not supported)
1
1
0x00
0xE0
Configuration characteristics = Bus and Self-Powered with Remote
Wakeup
8
MaxPower
Maximum power consumption of USB device from bus = 100 mA
1
0x32
Bus Powered Mode:
Offset Field
Description
Size (bytes) Value
7
8
bmAttributes
MaxPower
Configuration characteristics = Bus-Powered with Remote Wakeup
Maximum power consumption of USB device from bus = 500 mA
1
1
0xA0
0xFA
Interface Descriptor
The Interface Descriptor provides information about the single interface which the AT43312 supports.
Offset Field
Description
Size (bytes) Value
0
1
2
3
4
5
6
7
8
bLength
Define size of this descriptor = 9 bytes
Descriptor type = Interface
1
1
1
1
1
1
1
1
1
0x09
0x04
0x00
0x00
0x01
0x09
0x00
0x00
0x00
bDescriptorType
bInterfaceNumber
bAlternatSetting
bNumEndpoints
bInterfaceClass
bInterfaceSubClass
bInterfaceProtocol
iInterface
Number of interface = 1, index = 0
Alternate setting value for the interface identified in the prior field = 0
Number of endpoints used by this interface = 1
Class code = HUB_CLASSCODE = 09
Subclass code = 0
Protocol code = 0
Index of string descriptor describing this interface = not supported
AT43312
10
AT43312
Endpoint Descriptor
There is no endpoint descriptor for Endpoint0. This descriptor describes the Endpoint1 descriptor which the Hub uses for
status change report.
Offset Field
Description
Size (bytes) Value
0
1
2
3
4
bLength
Size of this descriptor = 7 bytes.
Descriptor type = Endpoint
1
1
1
1
2
0x07
0x05
0x81
0x03
bDescriptorType
bEndpointAddress
bmAttributes
The address of the IN endpoint
Transfer Type = Interrupt
wMaxPacketSize
Max. packet size Endpoint1 is capable of sending = 1 byte
0x01
0x00
6
bInterval
Interval for polling endpoint for data transfers = 256 ms
1
0xFF
Hub Descriptor
This descriptor describes the AT43312’s Hub and ports.
Offset Field
Definition
Size (bytes) Value
0
1
2
3
bDescLength
Define size of this descriptor = 9 bytes
Descriptor Type = HUB_DESCRIPTOR = 29
Number of downstream ports = 4
1
1
1
2
0x09
0x29
0x04
bDescriptor Type
bNbrPorts
wHubCharacteristics Hub's characteristics:
= Individual power switching
0x09
0x00
= Hub is not part of a compound device
= Individual Port Over-current Protection
5
bPwrOn2PwrGood
Time from the time power-on sequence begins on a port until power is
good on that port = 100ms.
1
0x32
6
7
bHubContrCurrent
DeviceRemovable
Maximum current requirements of the hub electronics = 100 mA.
1
1
0x64
0x00
Indicates if a port has removeable device. All downstream ports have
removable devices.
8
PortPwrCtrlMask
Indicates if a port is not affected by gang-mode power control request. All
the AT43312’s ports require manual SetPortFeature(PORT_POWER)
request to control the port’s power state.
1
0x1E
11
bits of the Controller Status Register described on page 6.
These bits are set or cleared depending whether the end-
point is stalled or not :
Standard Requests
Standard Requests, or commands, are sent to the
AT43312 from the Host on the AT43312's default pipe.
These requests are made using control transfers to
endpoint0. The request and request parameters are sent in
a Setup packet which consists of eight bytes. The following
sections describe which requests are supported by the
AT43312 and the corresponding responses, as well as
those requests not supported and responded with a STALL
packet. Please refer to the USB specifications for details
about the standard requests.
Current Endpoint Status First Byte
Second Byte
00H
Halt
01H
00H
Not halt
00H
Set_Address
Saves the value of bytes 2 and 3 in a temporary buffer, and
after successful completion of status stage, it will transfer
the value into the Hub_Address Register. This value will be
used as the Hub's address in all future transactions.
Clear_Feature [Device]
Disable remote wakeup feature.
Set_Configuration
Clear_Feature [Interface]
Sets bit 0 of the Controller_Status Register according to the
value of byte 2 of the Setup packet. The AT43312 has only
one configuration and it will set the bit only if byte 2 is either
00H or 01H, and bytes 3 to 7 are all zeroes. For any other
values, the Hub will respond with a STALL handshake
packet. If the value of byte 2 is 1, the AT43312 will be con-
figured. If 0, it will go to its unconfigured state.
Not supported, respond with a STALL.
Clear_
Endpoint]
Feature [
Clear an endpoint’s halt status bit if the condition causing
the stall has been removed.
Get_Configuration
Return one byte of data. Bit 0 will be a copy of bit 0 of the
Controller_Status Register. All other bits will be set to 0.
Set_Descriptor
Not supported. Will send a STALL handshake packet.
Get_Descriptor
Return the appropriate descriptor. The last word of the
Get_Descriptor request specifies the number of bytes
AT43312 is to return. If the requested descriptor is longer
than the requested number of bytes, AT43312 will return
only the requested number of bytes from the top of the
descriptor. If the requested descriptor is shorter than the
requested number of bytes, then the AT43312 indicates the
end of the control transfer by sending a short data packet.
Set_Feature [Device]
Enables its remote wakeup feature.
Set_Feature [Interface]
Not supported and will respond with a STALL.
Set_Feature [Endpoint]
Sets the stall status bit of the Controller Status Register.
The stalled endpoint now exhibits the same behavior as in
a stall condition.
Get_Interface
The AT43312 has a single interface with a value of 0. If it
receives a Get_Interface request with the value of 0x0000
as wIndex (bytes 2), and it will return a single byte with the
value 0x00. For any other value of wIndex, the AT43312
will return a STALL.
Set_Interface
The AT43312 has a single interface and responds with a
STALL if a Set_Interface request is received with a value
other than 0x0000 as wValue (alternative setting, bytes 2
and 3).
Get_Status [Device]
Sync_Frame
Returns two bytes of data, byte 0 and byte 1, in little endian
order Byte 0, Bit 0 = 1, identifying the AT43312 as a self-
powered device. Byte 0, Bit 1 = copy of bit 1 of the
Controller_Status Register. This bit reflects whether the
AT43312’s remote wakeup capability is enabled or dis-
abled. All other bits are set to 0. Bus-powered mode: Byte
0, Bit 0 = 0, identifying the AT43312 as a bus-powered
device.
Not supported. Will respond with a STALL packet.
Get_Status [Interface]
Responds with two bytes of data with all 0 value.
Get_Status [Endpoint]
Responds with two bytes of data. The first bit of the first
byte returned reflects the status of the endpoint halt status
AT43312
12
AT43312
Hub-specific Requests
Hub-specific requests or commands are sent from the Host
to the AT43312 using the Default Pipe (associated with
Endpoint0). These requests are made using control trans-
fers. The request and request parameters are sent in a
setup packet consisting of eight bytes. Please refer to the
USB specifications for details.
Get_Bus_State
The AT43311 samples the bus states of Ports 1, 2, 3, and
4, at each EOF2 and will store the value in a register known
as the Port_Bus_State registers. The value of the D- signal
(pin DMx) will be in bit 0 and the value of the D+ signal
(DPx) will be in bit 1 of each port’s Port_Bus_State register.
All other bits will be 0. The AT43311 responds with a
STALL if Port0 or a port higher than Port4 is addressed in
this request.
Clear_Hub_Feature
This request is used by the host to acknowledge local
power and hub overcurrent changes. Upon receipt of this
request with a wValue = 0, the AT43312 will clear the Local
Power Status Change bit. The AT43312 has a per port
overcurrent protection and does not report over-current on
a global basis. If this request has a wValue = 1, the
AT43312 will respond with a STALL.
Get_Hub_Descriptor
Returns the Hub Descriptor. The last word of the
Get_Hub_Descriptor request specifies the number of bytes
AT43312 is to return. If the requested number of bytes is
less than the 9 bytes length of the HubDescriptor, the
AT43312 will return only the requested number of bytes
from the top of the descriptor. If the requested number of
bytes is more than 9, then the returned data will be padded
with trailing bytes of zeroes.
Clear_Port_Feature
This request changes the status of a port according to
which port feature the request addressess. Not all the pos-
sible port features are supported, because some have no
meaning. Port features supported by the
Clear_Port_Feature request are: PORT_ENABLE,
PORT_SUSPEND, PORT_POWER, and all those affecting
the port status change bits. A request with an unsupported
feature, or if Port0 or a port higher than Port4 is addressed,
will cause the hub to respond with a STALL.
Get_Hub_Status
Returns the current Hub status that has changed since the
previous acknowledgment in the form of two words of data.
This is described in the following two tables. Word0 is the
Hub Status Field, wHubStatus, and Word1 is the Hub
Change Field, wHubChange.
13
Hub Status Field, wHubStatus
Bit
Description
0
Local Power Status, indicates the state of the local power supply.
0 = Local power supply good
1 = Local power supply lost
Over-Current Indicator, indicates over-current condition on a global hub basis. AT43312 reports over-current condition on a
per port basis therefore this bit is always read as 0.
2-15
Reserved. Always read as 0’s
Bus Powered Mode:
Bit
Description
0
Local Power Status. In the bus-powered configuration, the AT43312 will return a 0 if this bit is read.
Hub Change Field, wHubChange
Bit
Description
0
Local Power Status Change, C_HUB_OVER_POWER, corresponds to bit 0 of wHubStatus.
0 = No change has occurred in local power status
1 = Local power status has changed
1
Over-Current Indicator Change, C_HUB_OVER_CURRENT, corresponds to bit 1 of wHubStatus. AT43312 reports over-
current condition on a per port basis and therefore this bit is always read as 0.
2-15
Reserved. Always read as 0’s
Bus Powered Mode:
Bit
Description
0
Local Power Status Change. In the bus-powered configuration, the AT43312 will return as 0 if this bit is read.
Get_Port_Status
Returns the current port status and the states that have
changed since the previous acknowledgment in the form of
two words of data. This is described in the following two
tables. Word0 is the Port Status Field, and Word1 is the
Port Change Field. The Hub Controller will respond with a
STALL if Port0 or a port higher than Port4 is addressed in
this request.
AT43312
14
AT43312
Port Status Field, wPortStatus
Bit
Description
0
Current Connect Status: PORT_CONNECTION
0 = no device present on this port
1 = a device is present on this port
1
2
3
4
Port Enabled/Disabled: PORT_ENABLE
0 = Port is disabled
1 = Port is enabled
Suspend: PORT_SUSPEND
0 = Not suspended
1 = Suspended
Over-Current Indicator: PORT_OVER_CURRENT
0 = Power operation normal for this port
1 = Over-current condition exists for this port. Power to this port has been shut off
Reset: PORT_RESET
0 = Reset signalling not asserted
1 = Reset signalling asserted
5-7
8
Reserved. Always read as 0’s.
Port Power: PORT_POWER
0 = This port is powered OFF
1 = This port is powered ON
9
Low Speed Device Attached: PORT_LOW_SPEED
0 = Full Speed device attached to this port
1 = Low Speed device attached to this port
10-15 Reserved. Always read as 0’s
Port Change Field, wPortChange
Bit
Description
0
Connect Status Change: C_PORT_CONNECTION
0 = No change has occurred on Current Connect status
1 = Current Connect Status has changed
1
2
Port Enable/Disable Change: C_PORT_ENABLE
0 = No change has occurred on Port Enabled/Disabled status
1 = Port Enabled/Disabled status has changed
Suspend Change: C_PORT_SUSPEND
0 = No change
1 = Resume complete
3
Over-Current Indicator Change: C_PORT_OVER_CURRENT
0 = No change has occurred on Over-Current indicator
1 = Over-Current indicator has changed
4
Reset Change: C_PORT_RESET
0 = No change
1 = Reset complete
5-15
Reserved. Always read as 0’s.
15
Set_Hub_Descriptor
The AT43312 has one Hub Descriptor only and therefore
does not support this request. It will respond with a STALL.
Set_Port_Feature
This request changes the status of a port according to
which port feature the request addressess. Not all the pos-
sible port features are supported because some have no
meaning. Port features supported by the Set_Port_Feature
request are: PORT_ENABLE, PORT_SUSPEND,
PORT_REST and PORT_POWER. A request with an
unsupported feature, or if Port0 or a port higher than Port4
is addressed, will cause the hub to respond with a STALL.
Set_Hub_Feature
Sets a value reported in the Hub status. The status relates
to the local power and over-current. AT43312 does not
support this request and will respond with a STALL.
Port Feature Selector Table
Feature
Value
0
PORT_CONNECTION
PORT_ENABLE
1
PORT_SUSPEND
PORT_OVER_CURRENT
PORT_RESET
2
3
4
PORT_POWER
8
PORT_LOW _SPEED
C_PORT_CONNECTION
C_PORT_ENABLE
C_PORT_SUSPEND
C_PORT_OVER_CURRENT
C_PORT_RESET
9
16
17
18
19
20
AT43312
16
AT43312
Absolute Maximum Ratings
Operating Temperature.................................. -55°C to +125°C
*NOTICE:
Stresses beyond those listed below may cause
permanent damage to the device. This is a stress
rating only and functional operation of the device
at these or any other conditions beyond those
indicated in the operational sections of this spec-
ification is not implied. Exposure to absolute
maximum rating conditions for extended periods
may affect device reliability.
Storage Temperature .................................... -65°C to +150°C
Voltage on any pin with
Respect to Ground ..............................................-1.0V to 7.0V
Maximum Operating Voltage............................................. 6.6V
DC Output Current......................................................... 16 mA
DC Characteristics
The values shown in this table are valid for TA = 0oC to 85oC, VCC5 = 4.4 to 5.25V, VCC3 = 3.0V to 3.6V, unless otherwise
noted.
Power Supply
Symbol
VCC5
VCC3
VCCA
ICC5
Parameter
Condition
Min
4.40
3.0
Max
5.25
3.6
Unit
V
5V Power Supply
3.3V Power Supply
5V Analog Power Supply
5V Supply Current
3V Supply Current
Suspended Device Current
V
4.40
5.25
40
V
mA
mA
µA
ICC3
20
ICCS
200
USB Signals: DPx, DMx
Symbol
ILO
Parameter
Condition
Min
-10
0.2
Max
Unit
µA
V
Hi-Z Data Line Leakage
Differential Input Sensitivity
0 V < VIN < 3.3 V
DPx and DMx
+10
VDI
VCM
Differential Common Mode
Range
0.8
0.8
2.5
V
VSE
Single Ended Receiver
Threshold
2.0
0.3
3.6
V
V
V
VOL1
VOH1
Static Output Low
Static Output High
RL of 1.5 KΩ to 3.6 V
RL of 15 KΩ to GND
2.8
PWRx, STATx
Symbol
VOL1
Parameter
Condition
IOL = 8 mA
IOL = 4 mA
1 MHz
Min
Max
0.5
0.5
10
Unit
V
Output Low Level, STATx
Output Low Level, PWRx
Output capacitance
VOL2
V
Cout
pF
17
Oscillator Signals: OSC1, OSC2
Symbol
VLH
VHL
CX1
CX2
C12
Parameter
Condition
Min
0.47
0.67
Max
1.20
1.44
9
Unit
V
OSC1 switching level
OSC1 switching level
Input capacitance, OSC1
Output capacitance, OSC2
OSC1/2 capacitance
Start-up time
V
pF
pF
pF
ms
9
1
tsu
6 MHz, fundamental
10
DL
Drive level
VCC5 = 5V, 6 MHz crystal,
120 Ω equiv series
resistor
5
mW
Note:
OSC2 must not be used to drive other circuitry.
Comparator Signals: VREF, OVLx
Symbol
VOS
Parameter
Condition
Min
-20
80
Max
Unit
mV
dB
V
Input Offset voltage
Open loop gain
+20
A0
CMIRL
CMIRH
CMRR
CINR
Input CM range low
Input CM range high
CM rejection ratio
Input capacitance, VREF
Input capacitance, all other
0
VCC5
92
V
1 KHz
dB
pF
pF
10
6
CINL
AT43312
18
AT43312
AC Characteristics
Dpx, Dmx Driver Characteristics, Full Speed Operation
Symbol
TR
Parameter
Condition
CL = 50 pF
CL = 50 pF
Min
4
Max
20
Unit
ns
ns
%
Rise time
TF
Fall time
4
20
TRFM
VCRS
ZDRV
TR/TF matching
Output signal crossover
Driver output resistance(1)
90
1.3
29
110
2.0
44
V
Steady state drive
Ω
Note:
1. with external 27 Ω series resistor
Dpx, Dmx Data Source Timings, Full Speed Operation
Symbol
TDRATE
Parameter
Condition
Min
Max
Unit
Mbs
ms
Full Speed Data Rate
Frame Interval
Average Bit Rate
11.97
0.9995
12.03
1.0005
TFRAME
Source Diff Driver Jitter
To Next Transition
TDJ1
TDJ2
-3.5
-4.0
3.5
4.0
ns
ns
For Paired Transitions
TEOPT
Source EOP Width
160
175
ns
Differential to EOP Transistion
Skew
TDEOP
-2
5
ns
Recvr Data Jitter Tolerance
To Next Transition
TJR1
TJR2
-18.5
-9
18.5
9
ns
ns
For Paired Transitions
EOP Width at Receiver
Must Reject as EOP
Must Receive as EOP
TEOPR1
TEOPR2
40
82
ns
ns
19
DPx, DMx Driver Characteristics, Low Speed Operation
Symbol
TR
Parameter
Condition
CL = 50 pF
CL = 350 pF
CL = 50 pF
CL = 350 pF
Min
Max
Unit
ns
ns
ns
ns
%
Rise time
75
TR
Rise time
300
TF
Fall time
75
TF
Fall time
300
120
2.0
TRFM
VCRS
TR/TF matching
Output signal crossover
80
1.3
V
Dpx, Dmx Hub Timings, High Speed Operation
Symbol
Parameter
Condition
Min
Max
Unit
Hub Differential Data Delay
with cable
THDD1
THDD2
70
40
ns
ns
without cable
Hub Diff Driver Jitter
To Next Transition
THDJ1
THDJ2
-3
-1
3
1
ns
ns
For Paired Transitions
Data Bit Width Distortion
after SOP
TSOP
-5
3
ns
Hub EOP Delay Relative
to THDD
TEOPD
THESK
0
15
15
ns
ns
Hub EOP Output Width Skew
-15
Dpx, Dmx Hub Timings, Low Speed Operation
Symbol
Parameter
Condition
Min
Max
Unit
TLHDD
Hub Differential Data Delay
300
ns
Downstr Hub Diff Driver Jitter
To Next Transition
TLHDJ1
TLHDJ2
-45
-15
45
15
ns
ns
For Paired Transitions
Data Bit Width Distortion
after SOP
TSOP
-60
45
ns
Hub EOP Delay Relative
to THDD
TLEOPD
TLHESK
0
200
300
ns
ns
Hub EOP Output Width Skew
-300
AT43312
20
AT43312
Packaging Information
32R, 32-Lead, 0.440" Wide,
32P6
, 32-Lead, 0.600" Wide,
Plastic Gull Wing Small Outline (SOIC)
Dimensions in Inches and (MIllimeters)
Plastic Dual Inline Package (PDIP)
Dimensions in Inches and (Millimeters)
1.67(42.4)
1.64(41.7)
PIN
1
.566(14.4)
.530(13.5)
.090(2.29)
MAX
1.500(38.10) REF
.220(5.59)
MAX
.005(.127)
MIN
SEATING
PLANE
.065(1.65)
.015(.381)
.022(.559)
.014(.356)
.161(4.09)
.125(3.18)
.065(1.65)
.041(1.04)
.110(2.79)
.090(2.29)
.630(16.0)
.590(15.0)
0
15
REF
.012(.305)
.008(.203)
.690(17.5)
.610(15.5)
21
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