碌
PD6124A, 6600A
11. PIN FUNCTIONS
11.1
K
I/O
PIN (P
0
)
This is the 8-bit I/O pin for key-scan output. When the control register (P
1
) is set for the input port, the port can be
used as an 8-bit input pin. When the port is set for the input mode, all of these pins are pulled down to the V
SS
level
inside the LSI.
At reset (all cleared), the value of I/O mode and output latch becomes undefined.
Figure 11-1. K
I/O
Pin Organization
P
10
P
00
(P
1
)
Control register
P
0
K
I/O7
K
I/O6
K
I/O5
K
I/O4
K
I/O3
K
I/O2
K
I/O1
K
I/O0
11.2
K
I/O
PULL-DOWN RESISTOR CONFIGURATION
V
DD
Input/output selection
P-ch
Pin
N-ch
V
SS
CMOS
Output signal
Input signal
R
Pull-down resistor
N-ch
When K
I/O
is set to the input mode, pull-down resistor R is turned on.
9