M16C62_M Datasheet, PDF (378/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

Clock-Synchronous Serial I/O
Mitsubishi microcomputers
M16C / 62A 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
“1”
enable bit (TE) “0”
Transmit
“1”
buffer empty
flag (Tl)
“0”
“H”
CTSi
“L”
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 = “H” transfer enable bit = “0”
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 _{“1”}
empty flag
(TXEPT)
“0”
Transmit
“1”
interrupt request _{“0”}
bit (IR)
Cleared to “0” 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 = “0”.
• Transmit interrupt cause select bit = “0”.
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
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