Receive Operation In Csio Mode; Initial Settings For Csio Reception - Mitsubishi Electric M32R Series User Manual

Mitsubishi 32-bit risc single-chip microcomputers

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12.4 Receive Operation in CSIO Mode

To receive data in CSIO mode, initialize the serial I/O following the procedure described below.

Note, however, that because the receive shift clock is derived from operation of the transmit circuit,

you need to execute transmit operation even when you only want to receive data.

(1) Setting SIO Transmit/Receive Mode Register

• Set the register to CSIO mode

• Select the internal or an external clock

(2) Setting SIO Transmit Control Register

• Select the clock divider's divide-by ratio (when internal clock selected)

(3) Setting SIO Baud Rate Register

When the internal clock is selected, set a baud rate generator value. (Refer to Section 12.3.1,

"Setting the CSIO Baud Rate.")

(4) Setting SIO Interrupt Mask Register

• Enable or disable the transmit buffer empty interrupt (SIO Interrupt Mask Register)

• Select the cause of receive interrupt (receive finished/error) (Cause of Receive Interrupt Select

(5) Setting SIO Receive Control Register

Set the receive enable bit

(6) Setting the Interrupt Controller (SIO Transmit Interrupt Control Register)

When you use a transmit interrupt or receive interrupt during transmission/reception, set its

priority level.

(7) Setting the DMAC

When you generate a DMA transfer request to the internal DMAC when the transmit buffer is

empty or transmission is completed, set the DMAC. (Refer to Chapter 9, "DMAC.")

12.4 Receive Operation in CSIO Mode