M16C Datasheet, PDF (132/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER

Preliminary Specifications REV.B
Specifications in this manual are tentative and subject to change.
Mitsubishi microcomputers
M16C / 6N Group
Clock asynchronous serial I/O (UART) mode
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 13-3. Typical receive timing in UART mode
(a) Separate CTS/RTS pins function (UART0)
With the separate CTS/RTS bit (bit 6 at address 03B016) is set to “1”, the unit outputs/inputs the CTS
and RTS signals on different pins. (See Figure 13-4.) This function is valid only for UART0. Note that
if this function is selected, the CTS/RTS function for UART1 cannot be used.
Microcomputer
TXD0 (P63)
RXD0 (P62)
IC
IN
OUT
RTS0 (P60)
CTS0 (P64)
CTS
RTS
Figure 13-4. 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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