Datasheet

Section 9 I/O Ports
Rev.6.00 Sep. 27, 2007 Page 396 of 1268
REJ09B0220-0600
Port A Data Register (PADR)
Bit : 7 6 5 4 3 2 1 0
PA7DR PA6DR PA5DR PA4DR PA3DR PA2DR PA1DR PA0DR
Initial value : 0 0 0 0 0 0 0 0
R/W : R/W R/W R/W R/W R/W R/W R/W R/W
PADR is an 8-bit readable/writable register that stores output data for the port A pins (PA
7
to
PA
0
).
PADR is initialized to H'00 by a reset, and in hardware standby mode. It retains its prior state in
software standby mode.
Port A Register (PORTA)
Bit : 7 6 5 4 3 2 1 0
PA7 PA6 PA5 PA4 PA3 PA2 PA1 PA0
Initial value : —
*
—
*
—
*
—
*
—
*
—
*
—
*
—
*
R/W : R R R R R R R R
Note: * Determined by state of pins PA
7
to PA
0
.
PORTA is an 8-bit read-only register that shows the pin states. It cannot be written to. Writing of
output data for the port A pins (PA
7
to PA
0
) must always be performed on PADR.
If a port A read is performed while PADDR bits are set to 1, the PADR values are read. If a port A
read is performed while PADDR bits are cleared to 0, the pin states are read.
After a reset and in hardware standby mode, PORTA contents are determined by the pin states, as
PADDR and PADR are initialized. PORTA retains its prior state in software standby mode.