AT43USB320A_04 ATMEL [ATMEL Corporation], AT43USB320A_04 Datasheet - Page 72

• Manufacturer Part Number: AT43USB320A_04
• Description: Full-speed USB Microcontroller with an Embedded Hub
• Manufacturer: ATMEL [ATMEL Corporation]

Idle State
Setup Response State
72
AT43USB320A
The following information describes how the AT43USB320A’s USB hardware and firmware
operates during a control transfer between the host and the hub’s or function’s control
endpoint.
This is the default state from power-up.
The Function Interface Unit (FIU) receives a SETUP token with 8 bytes of data from the Host.
The FIU stores the data in the FIFO, sends an ACK back to the host and asserts an
RX_SETUP interrupt.
Legend:
1. SETUP token, Data from Host
2. ACK to Host
3. Store data in FIFO
4. Set RX SETUP → INT
DATA1/DATA0 = Data packet with DATA1 or DATA2 PID
DATA1(0) = Zero length DATA1 packet
Hardware
5. Read UISR
6. Read CSR0
7. Read Byte Count
8. Read FIFO
9. Parse command data
10. Write to H/FCAR0:
11. Set UIAR[EP0 INTACK] to clear the
a. If Control Read: set DIR, clear RX
b. If Control Write: clear DIR in CAR0
c. If no Data Stage: set Data End, clear
SETUP, fill FIFO, set TX Packet
Ready in CAR0
DIR, set Force STALL in CAR0
interrupt source
Firmware
1443E–USB–4/04