UPD75238 Datasheet, PDF (82/190 Pages) NEC – 4 BIT SINGLE-CHIP MICROCOMPUTER

µPD75238
(3) Functions of serial interface (channel 0) registers
(a) Serial operation mode register 0 (CSIM0)
Fig. 4-40 shows the format of serial operation mode register 0 (CSIM0).
CSIM0 is an 8-bit register which specifies a serial interface (channel 0) operation mode, serial clock,
wake-up function, and so forth.
CSIM0 is manipulated using an 8-bit memory manipulation instruction. The higher three bits can be
manipulated bit by bit. Each bit can be manipulated using its name.
Each bit may or may not allow read and/or write operation. (See Fig. 4-40.) Bit 6 allows bit test
operation only; any data written to this bit is invalid.
A RESET input clears all bits to 0.
Fig. 4-40 Format of Serial Operation Mode Register 0 (CSIM0) (1/3)
Address
7
6
FE0H
CSIE0 COI
5
4
3
2
1
0
WUP CSIM04 CSIM03 CSIM02 CSIM01 CSIM00
Symbol
CSIM0
Remark (R) : Read only
(W) : Write only
Serial clock selection bit (W)
Serial interface operation mode selection bit (W)
Wake-up function specification bit (W)
Signal from address comparator (R)
Serial interface operation enable/disable specification bit (W)
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