R8C/38T-A Group
21. Clock Synchronous Serial Interface
Under development Preliminary document
Specifications in this document are tentative and subject to change.
R01UH0241EJ0010 Rev.0.10
Page 467 of 730
Aug 05, 2011
21.2.6
SI Control Register 2 (SICR2)
In the SICR2 register, the bit functions differ between the SSU and I2C bus functions.
21.2.6.1
SSU Function
Notes:
1. All SFRs except the shift register, bits SCLO and SDAO, and bits BC0 to BC3 in the SIMR1 register.
2. When writing to the SDAO bit, write 0 to the SDAOP bit and write 0 to the SDAO bit simultaneously using the
MOV instruction.
3. Do not rewrite this bit in 4-wire bus communication mode.
4. For the data output after serial data transmission, the last bit value of the transmitted serial data is retained.
If the content of the SDAO bit is rewritten before or after serial data transmission, the change is immediately
reflected in the data output until transfer starts. Do not write to the SDAO bit during data transfer.
Address 000E7h (SICR2_0)
Bit
b7b6
b5b4b3
b2b1b0
Symbol
After Reset
0
111
1101
Bit
Symbol
Bit Name
Function
R/W
b0
—
Nothing is assigned. The write value must be 1. The read value is 1.
—
b1
SIRST
Control block reset bit
When a hang-up occurs due to communication
failure during operation, writing 1 initializes the
control block without setting ports or initializing
R/W
b2
—
Nothing is assigned. The write value must be 1. The read value is 1.
—
b3
SCLO
Reserved
R
b4
SDAOP
SDAO write protect bit
(2)If 0 is written, the output level can be changed by
the SDAO bit.
Writing 1 has no effect. The read value is 1.
R/W
b5
SDAO
Serial data output value control bit
(3) The serial data output can be monitored by reading
this bit:
0: Serial data output is low
1: Serial data output is high
0: Data output is set to low
1: Data output is set to high
R/W
b6
SCP
Reserved
The write value is invalid.
R/W
b7
BBSY