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M16C62_N Datasheet, PDF (350/621 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY | |||
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Clock-Synchronous Serial I/O
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
Example of wiring
Microcomputer
CLKi
TXDi
CTSi
(Note)
Receiver side IC
CLK
RXD
Port
Example of operation
Note : Since TXD2 pin is N-channel open drain,
this pin needs pull-up resistor.
Transfer clock
(1) Transmission enabled
(2) Confirming CTS
(3) Start transmission Tc
(4) Transmission is complete
(5) Transmit next data
Transmit
â1â
enable bit (TE) â0â
Transmit
â1â
buffer empty
flag (Tl)
â0â
âHâ
CTSi
âLâ
CLKi
Data is set to UARTi transmit buffer register
Transferred from UARTi transmit buffer register to UARTi transmit register
TCLK
Stopped pulsing because
Stopped pulsing because CTSi = âHâ transfer enable bit = â0â
TxDi
D0 D1 D2 D3 D4 D5 D6 D7
D0 D1 D2 D3 D4 D5 D6 D7
D0 D1 D2 D3 D4 D5 D6 D7
Transmit register â1â
empty flag
(TXEPT)
â0â
Transmit
â1â
interrupt request â0â
bit (IR)
Cleared to â0â when interrupt request is accepted, or cleared by software
Shown in ( ) are bit symbols.
The above timing applies to the following settings:
⢠Internal clock is selected.
⢠CTS function is selected.
⢠CLK polarity select bit = â0â.
⢠Transmit interrupt cause select bit = â0â.
Tc = TCLK = 2(n + 1) / fi
fi: frequency of BRGi count source (f1, f8, f32)
n: value set to BRGi
Figure 2.4.7. Operation timing of transmission in clock-synchronous serial I/O mode
335
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