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SERIAL INTERFACE
12
12-27
32185/32186 Group Hardware Manual
Rev.1.10 REJ09B0235-0110 May 15, 07
12.2.8 SIO Special Mode Registers
SIO0 Special Mode Register (S0SMOD)
<Address: H'0080 0118>
SIO1 Special Mode Register (S1SMOD)
<Address: H'0080 0128>
SIO2 Special Mode Register (S2SMOD)
<Address: H'0080 0138>
SIO3 Special Mode Register (S3SMOD)
<Address: H'0080 0148>
SIO4 Special Mode Register (S4SMOD)
<Address: H'0080 0A18>
SIO5 Special Mode Register (S5SMOD)
<Address: H'0080 0A28>
b0
123456
b7
CKPOL
00000000
SEL3PNT
SELFST
SELCLK
CSIBL
<Upon exiting reset: H’00>
b
Bit Name
Function
R
W
0–3
CSIBL
0000: 8 bits
R
W
CSIO bit length select bit
0001: 9 bits
0010: 10 bits
0011: 11 bits
0100: 12 bits
0101: 13 bits
0110: 14 bits
0111: 15 bits
1xxx: 16 bits
4
SELCLK
0: f(BCLK)/2
R
W
Clock divider count source select bit
1: f(BCLK)
5
SELFST
0: LSB-first
R
W
Transfer order select bit
1: MSB-first
6
SEL3PNT
0: 3-point sampling invalid
R
W
3-point sampling control bit
1: 3-point sampling valid
7
CKPOL
0: Transmit data output at SCLK falling edge
R
W
Transmit/receive clock polarity select bit
Receive data fetch at SCLK rising edge
1: Transmit data output at SCLK rising edge
Receive data fetch at SCLK falling edge
(1) CSIBL (CSIO Bit Length Select) bits (Bits 0–3)
These bits are effective only when the clock-synchronous serial interface was selected with the trans-
mitting/receiving mode register. They select the data length.
(2) SELCLK (Clock Divider Count Source Select) bit (Bit 4)
This bit is provided for selection of clock divider count source.
(3) SELFST (Transfer Order Select) bit (Bit 5)
This bit selects the data bit transfer order.
(4) SEL3PNT (3 Points Sampling Control) bit (Bit 6)
Setting this bit to “1” allows 3-point sampling of each signal of RxD input/SCLKI input with BCLK
period, and SIO operates with its majority output as RxD input/SCLKI input. RxD input and SCLKI
input cannot be controlled individually. Also, 3-point sampling for SCLKI becomes effective only at
CSIO mode and external clock selection.
12.2 Serial Interface Related Registers