Configuration Of Serial Interface - NEC mPD780024AS Series Preliminary User's Manual

14.2 Configuration of Serial Interface

The serial interface (SIO3n) consists of the following hardware.
Item
Register
Control register
Remark n = 0, 1
(1) Serial I/O shift register 3n (SIO3n)
This is an 8-bit register that performs parallel-serial conversion and serial transmit/receive (shift operations)
synchronized with the serial clock.
SIO3n is set by an 8-bit memory manipulation instruction.
When 1 is set to bit 7 (CSIE3n) of the serial operation mode register 3n (CSIM3n), a serial operation can be started
by writing data to or reading data from SIO3n.
When transmitting, data written to SIO3n is output to the serial output (SO3n).
When receiving, data is read from the serial input (SI3n) and written to SIO3n.
RESET input makes SIO3n undefined.
Caution Do not access SIO3n during a transfer operation unless the access is triggered by a transfer
start (read operation is disabled when MODEn = 0 and write operation is disabled when MODEn
= 1).
Remark n = 0, 1
CHAPTER 14 SERIAL INTERFACE (SIO3)
Table 14-1. Configuration of Serial Interface (SIO3n)
Serial I/O shift register 3n (SIO3n)
Serial operation mode register 3n (CSIM3n)
Preliminary User's Manual U16035EJ1V0UM
Configuration
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