NEC PD78052 User Manual page 315

CHAPTER 16 SERIAL INTERFACE CHANNEL 0 ( PD78054 Subseries)
(3) Register setting
The SBI mode is set with the serial operating mode register 0 (CSIM0), the serial bus interface control register
(SBIC), and the interrupt timing specify register (SINT).
(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.
Symbol
<7> <6> <5>
CSIM0 CSIE0 COI WUP
R/W Serial Interface Channel 0 Clock Selection
CSIM01 CSIM00
0 Input Clock to SCK0 pin from off-chip
1 0 8-bit timer register 2 (TM2) output
1 1 Clock specified with bits 0 to 3 of timer clock select register 3 (TCL3)
R/W
CSIM CSIM CSIM
PM25 P25 PM26 P26 PM27 P27
04 03 02
0
3-wire serial I/O mode (16.4.2, "3-wire serial I/O mode operation.")
Note 2 Note 2
0
1 0
1 0 0
1 1
2-wire serial I/O mode (see section 16.4.4, "2-wire serial I/O mode operation.")
R/W WUP Wake-up Function Control
0 Interrupt request signal generation with each serial transfer in any mode
Interrupt request signal generation when the address received after bus release
1
(when CMDD=RELD=1) matches the slave address register (SVA) data in SBI mode
R COI Slave Address Comparison Result Flag
0 Slave address register (SVA) not equal to serial I/O shift register 0 (SIO0) data
1 Slave address register (SVA) equal to serial I/O shift register 0 (SIO0) data
R/W CSIE0 Serial Interface Channel 0 Operation Control
0 Operation stopped
1 Operation enabled
Notes 1. Bit 6 (COI) is a read-only bit.
2. Can be used as a port.
3. To use the wake-up function (WUP = 1), clear the bit 5 (SIC) of the interrupt timing specify
register (SINT) to 0.
4. When CSIE0=0, COI becomes 0.
Remark : don't care
PM : Port mode register
P : Port output latch
4 3 2 1
CSIM04 CSIM03 CSIM02 CSIM01 CSIM00
Operation
Mode
0 0 0 1
SBI mode
Note 2 Note 2
0 1
Note 3
Note 4
0 Address After Reset
FF60H 00H
SI0/SB0/P25
Start Bit
Pin Function
P25 (CMOS
input/output)
MSB
SB0 (N-ch
open-drain
input/output)
R/W
R/W Note 1
SO0/SB1/P26 SCK0/P27
Pin Function Pin Function
SB1 (N-ch
open-drain
input/output)
SCK0 (CMOS
input/output)
P26 (CMOS
input/output)
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