NEC PD789488 User Manual page 231

Symbol <7> 6
CSIM1A0 CSIE10 DIR10
CSIE10
Shift register operation
0 Operation stopped
1 Operation enabled
DIR10
0 MSB
1 LSB
ATE0
0 3-wire serial mode
1 3-wire serial mode with automatic transmit/receive function
LSCK10
0 SCK10 is used as port (P23) when CSIE10 = 0.
SCK10 is used for clock output when CSIE10 = 1.
1 SCK10 is fixed to high-level output when CSIE10 = 0.
SCK10 is used for clock output when CSIE10 = 1.
SCL101 SCL100
0 0
0 1
1 0
1 1
Note When CSIE10 = 0 (SIO1A0 operation stop status), the SCK10/P23, SO10/P24, and SI10/P25 pins can
freely be used as port pins. Also, when CSIE10 is used for transmission only, the SI10/P25 pin can be
used as P25 (CMOS I/O) (set bit 7 (RE0) of ADTC0 to 0).
Remarks 1. f : Main system clock oscillation frequency
X
2. The parenthesized values apply to operation at f
CHAPTER 12 SERIAL INTERFACE 1A0
<5> <4> 3
ATE0 LSCK10 0
Specification of operation enable/disable
Cleared
Count operation enabled
Specification of first bit of serial transfer data
Selection of operation mode
Chip enable control of SCK10 pin
External clock input to SCK10 pin
2
f /2 (1.25 MHz)
X
3
f /2 (625 kHz)
X
4
f /2 (313 kHz)
X
User's Manual U15331EJ4V1UD
2 1 0
0 SCL101 SCL100
Serial counter
Port function
Serial function + port function
Selection of serial clock
= 5.0 MHz.
X
Address After reset R/W
FF78H 00H R/W
Note
Port
231