NEC uPD78P078 - Manual (Page 329)

CHAPTER 17 SERIAL INTERFACE CHANNEL 0 (
µ
PD78078 SUBSERIES)
329
<6> <5> 4 3 2 1 0 <7>
Symbol
CSIM0
CSIM01
0
1
Serial Interface Channel 0 Clock Selection
Input Clock to SCK0 pin from off-chip
8-bit timer register 2 (TM2) output
0
SBI mode (See 17.4.3 SBI mode operation.)
R/W
1 Clock specified with bits 0 to 3 of timer clock select register 3 (TCL3)
CSIM
04
0
CSIM00
x
0
1
FF60H 00H R/W Note 1
Address After Reset R/W
R/W CSIM
03
CSIM
02
PM25 P25 PM26 P26 PM27 P27
Operation
Mode
Start Bit
SI0/SB0/P25
Pin Function
SO0/SB1/P26
Pin Function
SCK0/P27
Pin Function
x
1 0
WUP
0
1
Wake-up Function Control Note 3
Interrupt request signal generation with each serial transfer in any mode
Interrupt request signal generation when the address received after bus release
(when CMDD = RELD = 1) matches the slave address register (SVA) data in SBI mode
R/W
1
MSB
LSB
1 x 0 0 0 1
Note 2
3-wire serial
l/O mode
SI0 Note 2
(Input)
SO0
(CMOS output)
SCK0 (CMOS
input/output)
2-wire serial I/O mode (See 17.4.4 2-wire serial I/O mode operation.) 1 1
Note 2
CSIE0 COI WUP CSIM04 CSIM03 CSIM02 CSIM01 CSIM00
CSIE0
0
Serial Interface Channel 0 Operation Control
Operation stopped
Operation enabled
R/W
1
17.4.2 3-wire serial I/O mode operation
The 3-wire serial I/O mode is valid for connection of peripheral I/O units and display controllers which incorporate
a conventional synchronous clocked serial interface as is the case with the 75X/XL, 78K, and 17K series.
Communication is carried out with three lines of serial clock (SCK0), serial output (SO0), and serial input (SI0).
(1) Register setting
The 3-wire serial I/O mode is set with the serial operating mode register 0 (CSIM0) and serial bus interface
control register (SBIC).
(a) Serial operating mode register 0 (CSIM0)
CSIM0 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets CSIM0 to 00H.
Notes 1. Bit 6 (COI) is a read-only bit.
2. Can be used as P25 (CMOS input/output) when used only for transmission.
3. Set WUP to 0 when the 3-wire serial I/O mode is selected.
Remark x : Don’t care
PMxx : Port mode register
Pxx : Port output latch