UPD784938 Datasheet, PDF (441/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

RESET
P30/SI1,
P13/SI2
Figure 18-10. 3-Wire Serial I/O Mode Block Diagram
8
CTXE1 CRXE1 DIR1 CSCK1
CTXE2 CRXE2 DIR2 CSCK2
Internal bus
8
Direction control circuit
8
Shift register
SO latch
DQ
P31/SO1,
P14/SO2
P27/SCK1,
P12/SCK2
N-ch open-drain output enable
Serial clock counter
Serial clock control circuit
Interrupt signal
generator
INTCSI1, INTCSI2
Selector
Baud rate generator
CSCK1, CSCK2
CSCK1, CSCK2