M16C62_N Datasheet, PDF (150/621 Pages) Renesas Technology Corp – 16-BIT SINGLE-CHIP MICROCOMPUTER M16C FAMILY

Clock asynchronous serial I/O (UART) mode
Mitsubishi microcomputers
M16C / 62 Group
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER
• 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
Stop bit
D0
D1 D7
Sampled “L”
Receive data taken in
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 1.19.18. Typical receive timing in UART mode
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(a) Separate CTS/RTS pins function (UART0)
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Setting the CTS/RTS separate bit (bit 6 of address 03B016) to "1" inputs/outputs the CTS signal and
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_______
_______
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RTS signal from different pins. Choose which to use, CTS or RTS, by use of the CTS/RTS function
select bit (bit 2 of address 03A416). This function is effective in UART0 only. With this function cho-
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_______ _______
sen, the user cannot use the CTS/RTS function. Set "0" both to the CTS/RTS function select bit (bit
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2 of address 03AC16) and to the CTS/RTS disable bit (bit 4 of address 03AC16).
Microcomputer
TXD0 (P63)
RXD0 (P62)
IC
IN
OUT
RTS0 (P60)
CTS
CTS0 (P64)
RTS
Note : The user cannot use CTS and RTS at the same time.
_______ _______
Figure 1.19.19. The separate CTS/RTS pins function usage
(b) Sleep mode (UART0, UART1)
This mode is used to transfer data between specific microcomputers among multiple microcomputers
connected using UARTi. The sleep mode is selected when the sleep select bit (bit 7 at addresses
03A016, 03A816) is set to “1” during reception. In this mode, the unit performs receive operation when
the MSB of the received data = “1” and does not perform receive operation when the MSB = “0”.
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