Datasheet

Section 10 I/O Ports
Rev.7.00 Mar. 18, 2009 page 511 of 1136
REJ09B0109-0700
10.9.7 Pin Functions
Port A pins also function as the pins for address outputs and interrupt inputs. The correspondence
between the register specification and the pin functions is shown below.
• PA7/A23/IRQ7, PA6/A22/IRQ6, PA5/A21/IRQ5
The pin function is switched as shown below according to the operating mode, bit EXPE, bits
A23E to A21E, bits ITS7 to ITS5 in ITSR, and bit PADDR.
Operating
mode
1, 2, 4 7
EXPE ⎯ 0 1
AxxE 0 1 ⎯ 0 1
PAnDDR 0 1 0 1 0 1 0 1 0 1
Pin
function
PAn
input
PAn
output
PAn
input
Address
output
PAn
input
PAn
output
PAn
input
PAn
output
PAn
input
Address
output
IRQn interrupt input
*
xx = 23 to 21, n = 7 to 5
Note: * IRQn input when ITSn = 0.
• PA4/A20/IRQ4
The pin function is switched as shown below according to the operating mode, bit EXPE, bit
A20E and bit PA4DDR.
Operating
mode
1, 2 4 7
EXPE ⎯ ⎯ 0 1
A20E ⎯ 0 1 ⎯ 0 1
PA4DDR ⎯ 0 1 0 1 0 1 0 1 0 1
Pin
function
Address
output
PA4
input
PA4
output
PA4
input
Address
output
PA4
input
PA4
output
PA4
input
PA4
output
PA4
input
Address
output
IRQ4 interrupt input
*
Note: * IRQ4 input when ITS4 = 0.