UPD78F0411GA-GAM-AX Datasheet, PDF (424/564 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

CHAPTER 16 MANCHESTER CODE GENERATOR
(3) Transmit operation
In Manchester code generator mode, data is transmitted in 1- to 8-bit units. Data bits are transmitted in
Manchester code format. Transmission is enabled if bit 7 (MC0PWR) of MCG control register 0 (MC0CTL0) is
set to 1.
The output value while a transmission is suspended can be set by using bit 0 (MC0OLV) of the MC0CTL0
register.
A transmission starts by writing a value to the MCG transmit buffer register (MC0TX) after setting the transmit
data bit length to the MCG transmit bit count specification register (MC0BIT). At the transmission start timing, the
MC0BIT value is transferred to the 3-bit counter and the data of MC0TX is transferred to the 8-bit shift register.
An interrupt request signal (INTMCG) occurs at the timing that the MC0TX value is transferred to the 8-bit shift
register. The 8-bit shift register is continuously shifted by the baud rate clock, and signal that is XORed with the
baud rate clock is output from the MCGO pin.
When continuous transmission is executed, the next data is set to MC0BIT and MC0TX during data transmission
after INTMCG occurs.
To transmit continuously, writing the next transfer data to MC0TX must be complete within the period (3) and (4)
in Figure 16-8. Rewrite the MC0BIT before writing to MC0TX during continuous transmission.
Figure 16-8. Timing of Manchester Code Generator Mode (LSB First) (1/4)
(1) Transmit timing (MC0OLV = 1, total transmit bit length = 8 bits)
MC0PWR
MC0OLV
MC0OSL _{“L”}
MC0BIT
3-bit counter
MC0TX
8-bit shift register
Baud rate clock
“111”
“111” “110” “101” “100” “011” “010” “001”
“000”
“10010110” (8-bit data)
“10010110” “x1001011” “xx100101” “xxx10010” “xxxx1001” “xxxxx100” “xxxxxx10”
“xxxxxxx1”
MCGO pin
MC0TSF
INTMCG
422
User’s Manual U18698EJ1V0UD