Datasheet

Section 8 I/O Ports
Rev. 4.00 Sep 27, 2006 page 271 of 1130
REJ09B0327-0400
8.11.4 MOS Input Pull-Up Function
Port A has a built-in MOS input pull-up function that can be controlled by software. This MOS
input pull-up function can be used in any operating mode, and can be specified as on or off on a
bit-by-bit basis.
When a PADDR bit is cleared to 0, setting the corresponding PAODR bit to 1 turns on the MOS
input pull-up for that pin. The MOS input pull-up for pins PA7 to PA4 is always off when IICS is
set to 1. When the keyboard buffer control pin function is selected for pins PA7 to PA2, the MOS
input pull-up is always off.
The MOS input pull-up function is in the off state after a reset and in hardware standby mode. The
prior state is retained in software standby mode.
Table 8.24 summarizes the MOS input pull-up states.
Table 8.24 MOS Input Pull-Up States (Port A)
Mode Reset
Hardware
Standby Mode
Software
Standby Mode
In Other
Operations
1, 2, 3 Off Off On/Off On/Off
Legend:
Off: MOS input pull-up is always off.
On/Off:On when PADDR = 0 and PAODR = 1; otherwise off.