Datasheet

Section 8 I/O Ports
Rev. 4.00 Sep 27, 2006 page 269 of 1130
REJ09B0327-0400
Pin Selection Method and Pin Functions
PA4/A20/PS2BC/
KIN12/CIN12
The pin function is switched as shown below according to the combination of
operating mode, the KBIOE bit in KBCR1H of the keyboard buffer controller,
the IOSE bit in SYSCR, and bit PA4DDR.
Operating
mode
Modes 1, 2 (EXPE = 0), 3 Mode 2 (EXPE = 1)
KBIOE 0 1 0 1
PA4DDR 0 1 — 01—
IOSE ———— 01—
Pin function PA4
input
pin
PA4
output
pin
PS2BC
output
pin
PA4
input
pin
A20
output
pin
PA4
output
pin
PS2BC
output
pin
KIN12 input pin, CIN12 input pin, PS2BC input pin
When the IICS bit in STCR is set to 1, this pin functions as a bus buffer. This
pin can always be used as the PS2BC, KIN12, or CIN12 input pin.
PA3/A19/PS2AD/
KIN11/CIN11
The pin function is switched as shown below according to the combination of
operating mode, the KBIOE bit in KBCR0H of the keyboard buffer controller,
the IOSE bit in SYSCR, and bit PA3DDR.
Operating
mode
Modes 1, 2 (EXPE = 0), 3 Mode 2 (EXPE = 1)
KBIOE 0 1 0 1
PA3DDR 0 1 — 01—
IOSE ———— 01—
Pin function PA3
input
pin
PA3
output
pin
PS2AD
output
pin
PA3
input
pin
A19
output
pin
PA3
output
pin
PS2AD
output
pin
KIN11 input pin, CIN11 input pin, PS2AD input pin
This pin can always be used as the PS2AD, KIN11, or CIN11 input pin.