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CHAPTER 14 SERIAL INTERFACE SIO3
User’s Manual U15798EJ2V0UD
14.4 Operations of Serial Interface SIO3
This section explains the two modes of serial interface SIO3.
14.4.1 Operation stop mode
Because serial transfer is not performed in this mode, the power consumption can be reduced.
In addition, pins can be used as normal I/O ports.
(1) Register settings
Operation stop mode is set by serial operation mode register 3 (CSIM3).
CSIM3 is set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets the value of this register to 00H.
Address: FFAFH After reset: 00H R/W
Symbol
7
6
5
4
3
2
1
0
CSIM3
CSIE3
0
0
0
0
MODE
SCL31
SCL30
CSIE3
SIO3 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 fu port function
Note 2
Notes 1.
When CSIE3 = 0 (SIO3 operation stop status), the SI3, SO3, and SCK3 pins can be used for port
functions.
2.
When CSIE3 = 1 (SIO3 operation enabled status), the SI3 pin can be used as a port pin if only the
transmit function is used, and the SO3 pin can be used as a port pin if only the receive-only mode
is used.
Содержание mPD780344 Series
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