
7542 Group
Rev.3.02 Oct 31, 2006 Page 22 of 134
REJ03B0006-0302
Fig. 21 Block diagram of ports (2)
(8) Port P1
0
Direction
register
Data bus
Port latch
Serial I/O1 enable bit
Receive enable bit
Serial I/O1 input
Capture 0 input control
P1
0
, P1
2
, P1
3
input level
selection bit
Capture 0 input
P1
0
, P1
2
, P1
3
, P3
6
, and P3
7
input level are switched to the CMOS/TTL level by the port P1P3 control register.
When the TTL level is selected, there is no hysteresis characteristics.
(9) Port P1
1
Data bus
Port latch
Serial I/O1 output
P1
1
/T
x
D
1
P-channel output disable bit
Direction
register
Serial I/O1 enable bit
Transmit enable bit
(10) Port P1
2
Serial I/O1 clock output
Serial I/O1 mode selection bit
Serial I/O1 enable bit
Serial I/O1 enable bit
Serial I/O1 synchronous
clock selection bit
Direction
register
Data bus
Port latch
Serial I/O1 clock input
P1
0
, P1
2
, P1
3
input level
selection bit
*
(12) Port P1
4
Data bus
Serial I/O1 ready output
Port latch
Direction
register
CNTR
0
interrupt input
Timer output
P1
0
, P1
2
, P1
3
input level
selection bit
Serial I/O1 mode selection bit
Serial I/O1 enable bit
S
RDY1
output enable bit
Data bus
Port latch
Direction
register
*
(11) Port P1
3
Data bus
Port latch
Direction
register
A/D converter input
Analog input pin
selection bit
(13) Ports P2
0
–P2
7
*
*
Pulse output mode