upd78f0730 Renesas Electronics Corporation., upd78f0730 Datasheet - Page 263

• Manufacturer Part Number: upd78f0730
• Description: 8-bit Single-chip Microcontroller
• Manufacturer: Renesas Electronics Corporation.

CHAPTER 11 SERIAL INTERFACE CSI10
(2) Communication operation
In the 3-wire serial I/O mode, data is transmitted or received in 8-bit units. Each bit of the data is transmitted or
received in synchronization with the serial clock.
Data can be transmitted or received if bit 6 (TRMD10) of serial operation mode register 10 (CSIM10) is 1.
Transmission/reception is started when a value is written to transmit buffer register 10 (SOTB10). In addition,
data can be received when bit 6 (TRMD10) of serial operation mode register 10 (CSIM10) is 0.
Reception is started when data is read from serial I/O shift register 10 (SIO10).
After communication has been started, bit 0 (CSOT10) of CSIM10 is set to 1. When communication of 8-bit data
has been completed, a communication completion interrupt request flag (CSIIF1n) is set, and CSOT10 is cleared
to 0. Then the next communication is enabled.
Caution Do not access the control register and data register when CSOT10 = 1 (during serial
communication).
Figure 11-5. Timing in 3-Wire Serial I/O Mode (1/2)
(a) Transmission/reception timing (Type 1: TRMD10 = 1, DIR10 = 0, CKP10 = 0, DAP10 = 0)
SCK10
Read/write trigger
SOTB10
55H (communication data)
SIO10
ABH
56H
ADH
5AH
B5H
6AH
D5H
AAH
CSOT10
INTCSI10
CSIIF10
SI10 (receive AAH)
SO10
55H is written to SOTB10.
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Preliminary User’s Manual U19014EJ1V0UD