CHAPTER 15 SERIAL INTERFACE CSI10
Preliminary User’s Manual U16315EJ1V0UD
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15.3 Registers Controlling Serial Interface CSI10
Serial interface CSI10 is controlled by the following two registers.
•
Serial operation mode register 10 (CSIM10)
•
Serial clock selection register 10 (CSIC10)
(1) Serial operation mode register 10 (CSIM10)
CSIM10 is used to select the operation mode and enable or disable operation.
CSIM10 can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input clears this register to 00H.
Figure 15-2. Format of Serial Operation Mode Register 10 (CSIM10)
Address: FF80H After reset: 00H R/W
Note 1
Symbol
7
6
5
4
3
2
1
0
CSIM10
CSIE10
TRMD10
0
DIR10
0
0
0
CSOT10
CSIE10
Operation control in 3-wire serial I/O mode
0
Stops operation (SI10/P11/R
X
D0, SO10/P12, and SCK10/P10/T
X
D0 pins can be used as general-
purpose port pins).
1
Enables operation (SI10/P11/R
X
D0, SO10/P12, and SCK10/P10/T
X
D0 pins are at active level).
TRMD10
Note 2
Transmit/receive mode control
0
Note 3
Receive mode (transmission disabled)
1
Transmit/receive mode
DIR10
Note 4
First bit specification
0
MSB
1
LSB
CSOT10
Note 5
Operation mode flag
0
Communication is stopped.
1
Communication is in progress.
Notes 1.
Bit 0 is read-only.
2.
Do not rewrite TRMD10 when CSOT10 = 1 (during serial communication).
3.
The SO10 pin is fixed to the low level when TRMD10 is 0. Reception is started when data is read from
SIO10.
4.
Do not rewrite DIR10 when CSOT10 = 1 (during serial communication).
5.
CSOT10 is cleared if CSIE10 is set to 0 (operation stopped).
Caution
Be sure to set bit 5 to 0.