M16C62_M Datasheet, PDF (402/615 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/60 SERIES

UART
Example of wiring
Microcomputer
TXDi
CTSi
Mitsubishi microcomputers
M16C / 62A Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
(Note)
Receiver side IC
RXD
Port
Note: Since TXD2 pin is N-channel open drain,
this pin needs pull-up resistor.
Example of operation
When confirming stop bit, stopped transfer clock once because CTS = “H”
Tc _{Started transfer clock again to start transmitting immediately after confirming CTS = “L”}
Transfer clock
(1) Transmission enabled
(4) Confirme stop bit
Transmit
“1”
enable bit (TE) _{“0”}
(2) Confirme CTS
(3) Start transmission
(5) Start transmission
Data is set in UARTi transmit buffer register
Transmit buffer ^{“1”}
empty flag (Tl) _{“0”}
Transferred from UARTi transmit buffer register to UARTi transmit register
CTSi
TxDi
“H”
“L”
Start
bit
Parity Stop
bit bit
Stopped pulsing because transfer enable bit = “0”
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
ST D0 D1
Transmit
register empty
“1”
flag (TXEPT) “0”
Transmit
“1”
interrupt
bit (IR)
request
“0”
Shown in ( ) are bit symbols.
Cleared to “0” when interrupt request is accepted, or cleared by software
The above timing applies to the following settings :
• Parity is enabled.
• One stop bit.
• CTS function is selected.
• Transmit interrupt cause select bit = “1”.
Tc = 16 (n + 1) / fi or 16 (n + 1) / fEXT
fi : frequency of BRGi count source (f1, f8, f32)
fEXT : frequency of BRGi count source (external clock)
n : value set to BRGi
Figure 2.5.8. Operation timing of transmission in UART mode
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