Sharp ER-A750 Service Manual page 65

18. IR communication
The ER-A750 has IR communication function which is softwarewisely
compatible with the ER-A460. Data is exchanged with the MPCA7
using the channel 1 (SCI1) of the serial communication interface of
the CPU.
18-1 CPU interface and modulator/demodulator
Here is its block diagram.
UATX
TXD1
UARX
RXD1
CPU
ASK modulation/
UASCK
SCK1
demodulation
491KHz
Baud rate X16
19. SRN
The SRN of the ER-A750 is compatible with the ER-A6IN.
20. Standard RS232
Two standard RS232 channels are compatible with the ER-A5RS.
However, while the ER-A5RS uses the IRQ2 terminal of the CPU for
interruption of the RS232, the ER-A750 cannot use the IRQ1 terminal
instead of it. (The IRQ2 terminal is used for IR as the SCK1 terminal.)
RPM850CB
IRTX
IRDA modulation/
IRRX
demodulation
Baud rate
X
IR unit
ASKRX
Divider
MPCA7
7.3728MHz
Fig. 20
7 – 35