32186 datasheet(587/1032 Pages) RENESAS

587 / 1032 page

SERIAL INTERFACE

12-39

32185/32186 Group Hardware Manual

Rev.1.10 REJ09B0235-0110 May 15, 07

12.4.2 Starting CSIO Reception

The serial interface starts receive operation when all of the following conditions are met after being initialized.

(1) Receive conditions when CSIO mode internal clock is selected

• The SIO Receive Control Register receive enable bit is set to "1."

• Transmit conditions are met. (See Section 12.3.3, “Starting CSIO Transmission.”)

(2) Receive conditions when CSIO mode external clock is selected

• The SIO Receive Control Register receive enable bit is set to "1."

• Transmit conditions are met. (See Section 12.3.3, “Starting CSIO Transmission.”)

Note: • The receive status bit is set to "1" at the time dummy data is set in the lower byte of the SIO

Transmit Buffer Register.

When the above conditions are met, the serial interface starts receiving 8 to 16 bits serial data synchro-

nously with the receive shift clock.

12.4.3 Processing at End of CSIO Reception

When data reception finishes, the following operation is automatically performed in hardware.

(1) When reception is completed normally

The reception finished (receive buffer full) bit is set to "1."

Notes: • An interrupt request is generated if the reception finished (receive buffer full) interrupt has been enabled.

• A DMA transfer request is generated.

(2) When an error occurred during reception

If an error (only overrun error in CSIO mode) occurred during reception, the overrun error bit and

receive error sum bit are set to "1."

Notes: • If the reception finished interrupt has been selected (by SIO Receive Interrupt Request Source Select

• If the receive error interrupt has been selected (by SIO Receive Interrupt Request Source

Select Register), a receive error interrupt request is generated when interrupt requests are

enabled. No DMA transfer requests are generated.

12.4 Receive Operation in CSIO Mode

32186 Datasheet(PDF) 587 Page - Renesas Technology Corp