NEC uPD78056Y User Manual
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CHAPTER 18 SERIAL INTERFACE CHANNEL 1
18.4.3 3-wire serial I/O mode operation with automatic transmit/receive function
This 3-wire serial I/O mode is used for transmission/reception of a maximum of 32-byte data without the use of
software. Once transfer is started, the data prestored in the RAM can be transmitted by the set number of bytes,
and data can be received and stored in the RAM by the set number of bytes.
Handshake signals (STB and BUSY) are supported by hardware to transmit/receive data continuously. OSD (On
Screen Display) LSI and peripheral LSI including LCD controller/driver can be connected without difficulty.
(1) Register setting
The 3-wire serial I/O mode with automatic transmit/receive function is set with the serial operating mode
register 1 (CSIM1), the automatic data transmit/receive control register (ADTC) and the automatic data
transmit/receive interval specify register (ADTI).
(a) Serial operating mode register 1 (CSIM1)
CSIM1 is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input sets CSIM1 to 00H.