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Chapter 13
Serial Interface SIO30
User’s Manual U16504EE1V1UD00
13.5 Serial Interface Operations
This section explains two modes of SIO30.
13.5.1 Operation stop mode
This mode is used if the serial transfers are not performed to reduce power consumption.
During the operation stop mode, the pins can be used as normal I/O ports as well.
Register settings
The operation stop mode can be set via the serial operation mode register (CSIM30).
CSIM30 can be set via 1-bit or 8-bit memory manipulation instructions.
The RESET input sets the value to 00H.
Figure 13-3:
Format of Serial Operation Mode Register (CSIM30)
Note:
When CSIE30 = 0 (SIO30 operation stop status), the pins SI30, SO30 and SCK30 can be used
for port functions.
<7>
6
5
4
3
2
1
0
R/W
Address
After
Reset
00H
CSIM30 CSIE30
0
0
0
0
MODE30 SCL301 SCL300 R/W
FFA8H
CSIE30
SIO30 Operation Enable/Disable Specification
Shift register operation
Serial counter
Port
0
Operation stop
Clear
Port function
Note 1
1
Operation enable
Count operation enable
Serial operation + port function