
SERIAL INTERFACE
12
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32185/32186 Group Hardware Manual
Rev.1.10 REJ09B0235-0110 May 15, 07
12.4 Receive Operation in CSIO Mode
12.4.1 Initialization for CSIO Reception
To receive data in CSIO mode, initialize the serial interface 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 interface is used for only receiving data.
(1) Setting SIO Special Mode Register
Set the data length selection in CSIO mode
Select the clock divider count source
Set the data bit transfer order
3-point sampling control
Select the clock polarity in CSIO mode
(2) Setting SIO Transmit/Receive Mode Register
Set the register to CSIO mode.
Select the internal or an external clock.
(3) Setting SIO Transmit Control Register
Select the clock divider's divide-by ratio (when internal clock selected).
(4) 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.”)
(5) 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 Mask Register).
(6) Setting SIO Receive Control Register
Set the receive enable bit.
(7) Setting Interrupt Controller (SIO Receive Interrupt Control Register)
To use receive interrupts, set their priority levels.
(8) Setting DMAC
Set up the DMAC when the DMA transfer is requested to the internal DMAC on completion of the
reception. (See Chapter 9, “DMAC.”)
(9) Selecting pin functions
Because the serial interface related pins serve dual purposes, set the pin functions for use as SIO
pins or input/output ports. (See Chapter 8, “Input/Output Ports and Pin Functions.”)
12.4 Receive Operation in CSIO Mode