M16C26 Datasheet, PDF (140/239 Pages) Renesas Technology Corp – 16-BIT CMOS SINGLE-CHIP MICROCOMPUTER M16C FAMILY / M16C/20 SERIES

Udenvdeelropment
Preliminary Specifications Rev. 0.9
Specifications in this manual are tentative
Clock Asynchronous Serial I/O (UART) Mode
and
subject to change.
SINGLE-CHIP 16-BIT
M16C/26 Group
CMOS MICROCOMPUTER
• Example of receive timing when transfer data is 8 bits long (parity disabled, one stop bit)
Tc
Transfer clock
Transmit enable
1
bit(TE)
0
Transmit buffer
1
empty flag(TI)
0
TxD2
Data is set in UART2 transmit buffer register
Note
Transferred from UART2 transmit buffer register to UARTi transmit register
Start
bit
Parity _Stop
bit
bit
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
ST D0 D1 D2 D3 D4 D5 D6 D7 P SP
Transmit register ¹
empty flag (TXEPT) ₀
Transmit interrupt ¹
request bit (IR)
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.
* Transmit interrupt cause select bit = 1 .
Tc = 16 (n + 1) / fi
fi : frequency of BRG2 count source (f1SIO, f2SIO, f8SIO, f32SIO)
n : value set to BRG2
Note: The transmit is started with overflow timing of BRG after having written in a value at the transmit buffer in the above timing.
Figure 1.15.20. Typical transmit timing in UART mode (UART2)
• Example of receive timing when transfer data is 8 bits long (parity disabled, one stop bit)
BRGi count
source
1
Receive enable bit
0
RxDi
Start bit
Sampled L
D0
D1 D7
Receive data taken in
Stop bit
Transfer clock
Receive
complete flag
RTSi
Receive interrupt
request bit
Reception triggered when transfer clock
1 is generated by falling edge of start bit
0
H
L
1
0
Transferred from UARTi receive register to
UARTi receive buffer register
Cleared to 0 when interrupt request is accepted, or cleared by software
The above timing applies to the following settings :
* Parity is disabled.
* One stop bit.
* RTS function is selected.
Figure 1.15.21. Typical receive timing in UART mode
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Renesas Technology Corp.