Datasheet

Section 8 I/O Ports
Rev. 3.00 Mar 21, 2006 page 206 of 788
REJ09B0300-0300
8.11.3 Port A Input Data Register (PAPIN)
PAPIN indicates the port A state.
Bit Bit Name Initial Value R/W Description
7 PA7PIN Undefined
*
R
6 PA6PIN Undefined
*
R
5 PA5PIN Undefined
*
R
4 PA4PIN Undefined
*
R
3 PA3PIN Undefined
*
R
2 PA2PIN Undefined
*
R
1 PA1PIN Undefined
*
R
0 PA0PIN Undefined
*
R
Reading PAPIN always returns the pin states.
PAPIN has the same address as PADDR. If a
write is performed, the port A settings will change.
Note: * The initial value is determined according to the PA7 to PA0 pin states.
8.11.4 Pin Functions
• PA7/A23/KIN15/CIN15/PS2CD
The pin function is switched as shown below according to the combination of operating mode,
the KBIOE bit in KBCRH_2 of the keyboard buffer controller, the IOSE bit in SYSCR, and
the PA7DDR bit.
Operating
Mode
Modes 1, 2 (EXPE = 0), 3 Mode 2 (EXPE = 1)
KBIOE 0 1 0 1
PA7DDR 0 1 — 0 1 —
IOSE ———— 0 1 —
PA7
input pin
PA7
output pin
PS2CD
output pin
PA7
input pin
A23
output pin
PA7
output pin
PS2CD
output pin
Pin Function
KIN15 input pin, CIN15 input pin, PS2CD input pin
*
Note: * When the KBIOE bit is set to 1 or the IICS bit in STCR is set to 1, this pin is an NMOS
open-drain output, and has direct bus drive capability. This pin can always be used as
the PS2CD, KIN15, or CIN15 input pin.