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DEVELOPING A USB SMARTCARD READER WITH ST7SCR

To finish the main loop, the CCID_BulkInMessage() function sends the Bulk-in message as an

answer to the previous Bulk-out message. The message is sent in a process that requires sev-

eral Bulk-in transactions (same concept as for the Bulk-out process).

In addition, the Abort request is implemented through the CCIDClassRequestAbort() function

called in the USB_Polling() function. For this purpose, the USB_Polling() function is called in

the PC_to_RDR_xxx() function. When this request is received from endpoint 0, a flag is set

and the command sequence number is memorized.

All commands are aborted until the next PC_to_RDR_Abort command with the correct se-

quence number is received.

1.2 FUNCTION DESCRIPTION

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void CCID_Init(void)

This function initializes the flags and status variables for the state machine process.

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void CCID_Init_IT(void)

This function initializes the state machine and switches off the VccCard after a USB reset

done by the PC Host. It can only be called by an interrupt routine.

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void CCID_Suspend_IT(void)

This function initializes the state machine and the card interface hardware after a resume from

USB suspend mode.

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void CCID_BulkOutMessage(void)

This function manages the state machine during USB Bulk Out message reception. It fills the

message buffer with a maximum of 271 bytes.

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void CCID_BulkInMessage(void)

This function manages the state machine during the USB Bulk In message transmission. It

sends the buffer content as a message with a maximum of 271 bytes.

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void CCID_DispatchMessage(void)

This function identifies the USB Bulk Out received message and calls the corresponding func-

tions to process it : PC_to_RDR_xxx() and RDR_to_PC_xxx().

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void CCID_IntMessage(void)

This function verifies the slot status and sends an interrupt In message if needed.