Receive Operation In Csio Mode; Initialization For Csio Reception - Renesas M32R/ECU Series User Manual

12

12.4 Receive Operation in CSIO Mode

12.4.1 Initialization for CSIO Reception

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 by an operation of the transmit circuit, transmit operation must
always be executed even when the serial I/O is used for only receiving 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. (See Section 12.3.1, "Setting the CSIO
Baud Rate.")
(4) Setting SIO interrupt related registers
• Select the source of receive interrupt request (reception finished or error) (SIO Interrupt Request Source
Select Register).
• Enable or disable receive interrupts (SIO Interrupt Request Enable Register).
(5) Setting SIO Receive Control Register
• Set the receive enable bit.
(6) Setting Interrupt Controller (SIO Transmit Interrupt Control Register)
To use receive interrupts, set their priority levels.
(7) Setting DMAC
Set up the DMAC when the DMA transfer is requested to the internal DMAC on completion of the transmission.
(See Chapter 9, "DMAC.")
12.4 Receive Operation in CSIO Mode
12-32
Serial I/O
32180 Group User's Manual (Rev.1.0)