NEC PD78F9488 User Manual
Page 231
CHAPTER 12 SERIAL INTERFACE 1A0
User’s Manual U15331EJ4V1UD
231
Symbol
<7> 6 <5>
<4> 3 2 1 0
Address
After
reset
R/W
CSIM1A0 CSIE10 DIR10 ATE0 LSCK10
0
0
SCL101 SCL100 FF78H
00H
R/W
Specification of operation enable/disable
CSIE10
Shift register operation
Serial counter
Port
Note
0
Operation stopped
Cleared
Port function
1
Operation enabled
Count operation enabled
Serial function + port function
DIR10
Specification of first bit of serial transfer data
0 MSB
1 LSB
ATE0
Selection of operation mode
0
3-wire serial mode
1
3-wire serial mode with automatic transmit/receive function
LSCK10
Chip enable control of SCK10 pin
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
Selection of serial clock
0
0
External clock input to SCK10 pin
0 1
f
X
/2
2
(1.25 MHz)
1 0
f
X
/2
3
(625 kHz)
1 1
f
X
/2
4
(313 kHz)
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
X
: Main system clock oscillation frequency
2. The parenthesized values apply to operation at f
X
= 5.0 MHz.