UPD70F3114 Datasheet, PDF (425/692 Pages) NEC – 32-Bit Single-Chip Microcontrollers

CHAPTER 10 SERIAL INTERFACE FUNCTION
(b) Ending procedure
The procedure for ending continuous transmission is shown below.
Figure 10-7. Continuous Transmission End Procedure
TXD0 (output)
<6> <7>
INTST0 (output)
TXB0 register Data (m − 1)
Transmit shift register
ASIF0 register
(TXBF0, TXSF0 bits)
11
01
UARTCAE0 bit
or
TXE0 bit
Start
bit
<8>
Data (m − 1)
Stop
bit
<9>
Start
bit
<10>
Data (m)
Stop
bit
<11>
Data (m − 1)
11
Data (m)
Data (m)
01
FFH
00
Transmission End Procedure
• Read ASIF0 register (confirm that TXBF0 bit = 0)
• Write data (m)
• Read ASIF0 register (confirm that TXSF0 bit = 1)
There is no write data
• Read ASIF0 register (confirm that TXSF0 bit = 0)
• Clear (0) the UARTCAE0 bit or TXE0 bit
Internal Operation
<6> Transmission of data (m − 2) is in
progress
<7> INTST0 interrupt occurs
<8> Generate start bit
Start data (m − 1) transmission
<<Transmission in progress>>
<9> INTST0 interrupt occurs
<10> Generate start bit
Start data (m) transmission
<<Transmission in progress>>
<11> Generate INTST0 interrupt
Initialize internal circuits
ASIF0 Register
TXBF0 TXSF0
1
1
0
1
0
1
1
1
0
1
0
1
0
0
0
0
User’s Manual U15195EJ5V0UD
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