UPD78F9418A NEC, UPD78F9418A Datasheet - Page 193

• Manufacturer Part Number: UPD78F9418A
• Description: (UPD7894xxA) 8-Bit Single Chip Microcontrollers
• Manufacturer: NEC

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TxD (Output)
TxD (Output)
(c)
INTST00
INTST00
Figure 13-8. Asynchronous Serial Interface Transmission Completion Interrupt Timing
Transmission
A transmit operation is started by writing transmit data to transmit shift register 00 (TXS00). The start
bit, parity bit and stop bit(s) are added automatically.
When the transmit operation starts, the data in TXS00 is shifted out, and when TXS00 is empty, a
transmission completion interrupt (INTST00) is generated.
Caution Do not rewrite asynchronous serial interface mode register 00 (ASIM00) during a
transmit operation.
transmission may not operate correctly (the normal state is restored by RESET input).
Whether transmission is in progress or not can be judged by software using a
transmission completion interrupt (INTST00) or the interrupt request flag (STIF00) set
by INTST00.
Start
Start
CHAPTER 13 SERIAL INTERFACE 00
D0
D0
User’s Manual U13952EJ3V0UD
D1
D1
If ASIM00 is rewritten during transmission, subsequent
(b) Stop bit length: 2
(a) Stop bit length: 1
D2
D2
D6
D6
D7
D7
Parity
Parity
Stop
Stop
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