Serial Operating Mode Register 1 Format - NEC PD78056F User Manual

(2) Serial operating mode register 1 (CSIM1)
This register sets serial interface channel 1 serial clock, operating mode, operation enable/stop and automatic
transmit/receive operation enable/stop.
CSIM1 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets CSIM1 to 00H.
Figure 18-3. Serial Operating Mode Register 1 Format
Symbol
7 6 5
CSIM1 CSIE1 DIR ATE
CSIM11 CSIM10
0 Clock externally input to SCK1 pin
1 0 8-bit timer register 2 (TM2) output
1 1 Clock specified with bits 4 to 7 of timer clock select register 3 (TCL3)
ATE
0 3-wire serial I/O mode
3-wire serial I/O mode with automatic transmit/receive function
1
DIR
0
1
CSIE1 CSIM11
PM20 P20 PM21 P21 PM22
Note 2 Note 2 Note 2 Note 2 Note 2
0
0
Note 3 Note 3
1 1 0
1
Notes 1. If the external clock input has been selected with CSIM11 set to 0, set bit 1 (BUSY1) and bit 2 (STRB)
of the automatic data transmit/receive control register (ADTC) to 0, 0.
2. Can be used freely as port function.
3. Can be used as P20 (CMOS input/output) when only transmitter is used (clear bit 7 (RE) of ADTC to 0).
Remark : Don't care
PMXX : Port Mode Register
PXX : Port Output Latch
CHAPTER 18 SERIAL INTERFACE CHANNEL 1
4 3 2 1 0
0 0 0
CSIM11 CSIM10
Serial Interface Channel 1 Clock Selection
Note 1
Serial Interface Channel 1 Operating Mode Selection
Start Bit
MSB
LSB
Shift Register Serial Clock Counter
P22
1 Operation Operation Control
Note 2
Operation
stop
Operation
1
enable
0
0 1
Address After Reset R/W
FF68H 00H R/W
SI1 Pin Function
SI1/P20
(Input)
SI1/P20 Pin SO1/P21 Pin
Function
Clear P20 (CMOS
input/output)
Count SI1 Note 3 SO1 (CMOS
(input)
operation
SO1 Pin Function
SO1
(CMOS output)
SCK1/P22
Function Pin Function
P21 (CMOS P22 (CMOS
input/output) input/output)
SCK1
output) (Input)
SCK1
(CMOS
output)
393