Initial Settings For Csio Transmission - Mitsubishi Electric M32R Series User Manual

Mitsubishi 32-bit risc single-chip microcomputers

Table of Contents

12.3.2 Initial Settings for CSIO Transmission

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

(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)

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

When you use a transmit buffer empty interrupt during transmission, set its priority level.

(6) Setting DMAC

When you issue DMA transfer requests to the internal DMAC when the transmit buffer is empty,

set the DMAC. (Refer to Chapter 9, "DMAC.")

(7) Selecting pin functions

Because the serial I/O related pins serve dual purposes (shared with input/output ports), set pin

functions. (Refer to Chapter 8, "Input/Output Ports and Pin Functions.")

12.3 Transmit Operation in CSIO Mode