Cypress Semiconductor SL811HS Manual do Utilizador descarregar pdf (Página 37)

Cypress Semiconductor Corporation

SL811HS and SL811HST: Application Notes

and specifications contained in this document are subject to change without

notice.

Date: 07/26/01

Revision: 1.21

Page: 37

5.1.1 SETUP Transaction

The SETUP transaction is a USB Host specific command that requests USB device information

whenever a USB device is attached.

USB Trace 6: SETUP Transaction

SYNC SETUP ADDR ENDP CRC5 EOP IDLE

SYNC DATA0 DATA PAYLOAD CRC16 EOP IDLE

SYNC ACK EOP IDLE

Note: Data payload for SETUP Token is 8 bytes.

Depending on the wLength of the transaction descriptor, the SETUP transaction is followed by

either one or more IN transactions that the host requests from the device. See example below

showing an instance of more than one IN transaction.

5.1.2 Control Read

The SL811HS read IN Token from USB device, which is always started with DATA1 during the

Data phase. SL811HS toggles to DATA0 then DATA1 and so on.

USB Trace 7: IN Transaction from Device to Host

To transfer 18-byte from device to host, it takes 3 IN transactions with 8-byte data payload.

PACKET # SYNC IN ADDR ENDP CRC5 EOP IDLE

PACKET # SYNC DATA1 8-BYTE DATA PAYLOAD CRC16 EOP IDLE

PACKET # SYNC ACK EOP IDLE

PACKET # SYNC IN ADDR ENDP CRC5 EOP IDLE

PACKET # SYNC DATA0 8-BYTE DATA PAYLOAD CRC16 EOP IDLE

PACKET # SYNC ACK EOP IDLE

PACKET # SYNC IN ADDR ENDP CRC5 EOP IDLE

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