Datasheet

Section 8 I/O Ports
Rev. 3.00 Mar 21, 2006 page 208 of 788
REJ09B0300-0300
• PA4/A20/KIN12/CIN12/PS2BC
The pin function is switched as shown below according to the combination of operating mode,
the KBIOE bit in KBCRH_1 of the keyboard buffer controller, the IOSE bit in SYSCR, and
the PA4DDR bit.
Operating
Mode
Modes 1, 2 (EXPE = 0), 3 Mode 2 (EXPE = 1)
KBIOE 0 1 0 1
PA4DDR 0 1 — 0 1 —
IOSE ———— 0 1 —
PA4
input pin
PA4
output pin
PS2BC
output pin
PA4
input pin
A20
output pin
PA4
output pin
PS2BC
output pin
Pin Function
KIN12 input pin, CIN12 input pin, PS2BC 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 PS2BC, KIN12, or CIN12 input pin.
• PA3/A19/KIN11/CIN11/PS2AD
The pin function is switched as shown below according to the combination of operating mode,
the KBIOE bit in KBCRH_0 of the keyboard buffer controller, the IOSE bit in SYSCR, and
the PA3DDR bit.
Operating
Mode
Modes 1, 2 (EXPE = 0), 3 Mode 2 (EXPE = 1)
KBIOE 0 1 0 1
PA3DDR 0 1 — 0 1 —
IOSE ———— 0 1 —
PA3
input pin
PA3
output pin
PS2AD
output pin
PA3
input pin
A19
output pin
PA3
output pin
PS2AD
output pin
Pin Function
KIN11 input pin, CIN11 input pin, PS2AD input pin
*
Note: * When the KBIOE bit 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 PS2AD, KIN11, or CIN11 input
pin.