UPD75518 NEC, UPD75518 Datasheet - Page 112

• Manufacturer Part Number: UPD75518
• Description: 4 BIT SINGLE-CHIP MICROCOMPUTER
• Manufacturer: NEC

112
4.9 SERIAL INTERFACE (CHANNEL 1)
4.9.1 Serial Interface (Channel 1) Functions
• Operation halt mode
• Three-wire serial I/O mode
4.9.2 Serial Interface (Channel 1) Configuration
8-bit data transfer is performed using three lines: Serial clock (SCK1), serial output (SO1), and serial input
(SI1).
The three-wire serial I/O mode allows full-duplex transmission, so data transfer can be performed at higher
speed.
The three-wire serial I/O mode enables connections to be made with the 75X series, 78K series, and many
other types of peripheral I/O devices.
The PD75518(A) has two modes. The functions of the two modes are outlined below.
This mode is used when serial transfer is not performed. This mode reduces power consumption.
Eight-bit data transfer always starts the MSB.
Fig. 4-54 shows the block diagram of the serial interface (channel 1).
PD75518(A)