Panasonic MN101C77C User Manual

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IV - 19
Chapter 4    I/O Ports
Port 2
Figure 4-4-2    Block Diagram (P20, P22 to P24)
4-4-3
Block Diagram
Figure 4-4-3    Block Diagram (P21)
R
D
L
Q
Reset
Write
Read
Read
Pull-up resistor control
Port input data
P2PLU0,2-4
P2IN0,2-4
P20,P22-P24
External interrupt
Schmitt trigger input
R
D
L
Q
Reset
Write
Read
D
L
Q
Write
Read
R
Reset
I/O direction control
Port outut data
Data bus
P2DIR0,2-4
P2OUT0,2-4
R
D
L
Q
Reset
Write
Read
Read
Pull-up resistor control
Port input data
NFCTR register bp7
AC zero-cross 
detection circuit
M
U
X
P2PLU1
P2IN1
1
0
P21
AC zero-cross input
External intrerrupt
Schmitt trigger input
R
D
L
Q
Reset
Write
Read
D
L
Q
Write
Read
R
Reset
I/O direction control
Port output data
Data bus
P2DIR1
P2OUT1