7470_N Datasheet, PDF (129/354 Pages) Renesas Technology Corp – 8-BIT SINGLE-CHIP MICROCOMPUTER 740 FAMILY / 7470 SERIES

HARDWARE
1.13 Serial I/O
1
Synchronous clock
b0 4
D0
P14/RxD
Receive shift register
Serial I/O status
register
0
Synchronous clock
(Address 00E116)
1
2
b1
b0
D3 D2 D1D0
Interrupt request
0
P14/RxD
Receive shift register
register 1
3
Synchronous clock
Receive shift
(Address 00FC16)
1
b5
register
D7 D6 D5D4 D3 D2 D1D0
Receive data transfer
(Address 00E016) Receive buffer register
Fig. 1.13B.4 Receive operation of clock synchronous serial I/O
Synchronous clock
RxD pin
D0
D1
D2
D3
D4
D5
D6
D7
Writing data to transmit shift register
Reading into receive shift register
SRDY pin
Receive buffer register
read signal
Receive buffer full flag
Receive enable bit
Receive interrupt request bit
A
A:• Clearing by writing “0” to the receive interrupt request bit.
• Clearing by accepting the receive interrupt.
Fig. 1.13B.5 Receive timing chart of clock synchronous serial I/O
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7470/7471/7477/7478 GROUP USER’S MANUAL