AT43USB325E-AU Atmel, AT43USB325E-AU Datasheet - Page 71

• Manufacturer Part Number: AT43USB325E-AU
• Description: IC USB KEYBOARD CTRLR 64LQFP
• Manufacturer: Atmel
• Series: AVR®r

Specifications of AT43USB325E-AU

• Applications: Keyboard Controller
• Core Processor: AVR
• Program Memory Type: SRAM (16 kB)
• Controller Series: AT43USB
• Ram Size: 512 x 8
• Interface: SPI, 3-Wire Serial
• Number Of I /o: 42
• Voltage - Supply: 4.4 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8.2
8.2.1
8.2.1.1
8.2.2
8.2.2.1
3355C–USB–4/05
USB Registers
Hub Address Register – HADDR
Function Address Register – FADDR
Hub Address Register – HADDR
Function Address Register – FADDR
The following sections describe the registers of the AT43USB325’s USB hub and function units.
Reading a bit for which the microcontroller does not have read access will yield a zero value
result. Writing to a bit for which the microcontroller does not have write access has no effect.
The USB hub contains an address register that contains the hub address assigned by the host.
This Hub Address Register must be programmed by the microcontroller once it has received a
SET_ADDRESS request from the host. The USB hardware uses the new address only after the
status phase of the transaction is completed when the microcontroller has enabled the new
address by setting bit 0 of the Global State Register. After power-up or reset, this register will
contain the value of 0x00.
• Bit 7 – SAEN: Single Address Enable
The Single Address Enable bit allows the microcontroller to configure the AT43USB325 into a
single address or a composite device. Once this capability is enabled, the hub endpoint 0
(HEP0) is converted from a control endpoint to a programmable function endpoint FEP3; all the
endpoints would then operate on the single address.
• Bit 6..0 – HADD6...0: Hub Address[6:0]
The USB function contains an address register that contains the function address assigned by
the host. This Function Address Register must be programmed by the microcontroller once it
has received a SET_ADDRESS request from the host and completed the status phase of the
transaction. After power up or reset, this register will contain the value of 0x00.
• Bit 7 – FEN: Function Enable
The Function Enable bit (FEN) allows the firmware to enable or disable the function endpoints.
The firmware will set this bit after receipt of a reset through the hub, SetPortFea-
ture[PORT_RESET]. Once this bit is set, the USB hardware passes to and from the host.
When the Single Address bit is set, the condition of FEN is ignored.
• Bit 6..0 – FADD6...0: Function Address[6:0]
Read/Write
Initial Value
Initial Value
Read/Write
$1FEF
$1FEE
Bit
Bit
SAEN
R/W
FEN
R/W
7
0
7
0
HADD6
FADD6
R/W
R/W
6
0
6
0
HADD5
FADD5
R/W
R/W
5
0
5
0
HADD4
FADD4
R/W
R/W
4
0
4
0
HADD3
FADD3
R/W
R/W
3
0
3
0
HADD2
FADD2
R/W
R/W
2
0
2
0
AT43USB325
HADD1
FADD1
R/W
R/W
1
0
1
0
HADD0
FADD0
R/W
R/W
0
0
0
0
HADDR
FADDR
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