UPD784938 Datasheet, PDF (457/733 Pages) NEC – 16-Bit Single-Chip Microcontrollers

CHAPTER 19 3-WIRE SERIAL I/O MODE
The µPD784938 has two channels of serial interfaces in 3-wire serial I/O mode (IOE0/IOE3).
The two channels of IOE have identical functions. Unless otherwise specified, therefore, IOE0 is explained in this chapter.
To use IOE3, refer to Table 19-1 for the register name, bit name, and pin name of IOE3.
Table 19-1. Differences in Name between IOE0 and IOE3
Pin name
Item
Clocked serial interface mode register
Clocked serial interface mode register bit names
Serial shift register
Interrupt request name
IOE0
P32/SCK0
P27/SI0
P33/SO0
CSIM
ENCSI, DIR, CRXE, MOD,
SELCL2 to SELCL0
SIO
INTCSI
IOE3
P105/SCK3
P106/SI3
P107/SO3
CSIM3
ENCSI3, DIR3, CRXE3, MOD3,
SELCL32 to SELCL30
SIO3
INTCSI3
19.1 Function
In the 3-wire serial I/O mode (MSB/LSB first), basically, three lines are used for communication: serial clock (SCK0),
serial data output (SO0), and serial data input (SI0). Generally, a handshake line is necessary for checking the
communication status.
Preliminary User’s Manual U13987EJ1V0UM00
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