M306V5ME Datasheet, PDF (112/262 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER and ON-SCREEN DISPLAY CONTROLLER

MITSUBISHI MICROCOMPUTERS
M306V5ME-XXXSP
M306V5EESP
SINGLE-CHIP 16-BIT CMOS MICROCOMPUTER with CLOSED CAPTION DECODER
and ON-SCREEN DISPLAY CONTROLLER
(4) Bus collision detection function and other functions (UART2)
This function is to sample the output level of the TxD pin and the input level of the RxD pin at the rising
edge of the transfer clock; if their values are different, then an interrupt request occurs. Figure 2.11.26
shows the example of detection timing of a buss collision (in UART mode).
And also, bit 5 of the special UART2 mode register is used as the selection bit for auto clear function
select bit of enable bit. Setting this bit to “1” automatically resets the transmit enable bit to “0” when “1”
is set in the bus collision detection interrupt request bit (nonconformity) (refer to Figure 2.11.25).
Bit 6 of the special UART2 mode register is used as the transmit start condition select bit. Setting this
bit to “1” starts the TxD transmission in synchronization with the falling edge of the RxD terminal (refer
to Figure 2.11.26).
Transfer clock ^{“H”}
“L”
TxD2 ^{“H”}
ST
“L”
RxD2 ^{“H”}
ST
“L”
Bus collision detection _{“1”}
interrupt request signal _{“0”}
Bus collision detection _{“1”}
interrupt request bit _{“0”}
Figure 2.11.25 Detection timing of a bus collision (in UART mode)
Transmit start condition select bit (Bit 6 of the UART2 special mode register)
0: In normal state
CLK
TxD
Enabling transmission
With "1: falling edge of RxD2" selected
CLK
TxD
RxD
Figure 2.11.26 Some other functions
112
SP
SP
ST : Start bit
SP : Stop bit
Rev. 1.0