Datasheet

Section 8 I/O Ports
Rev. 4.00 Sep 27, 2006 page 278 of 1130
REJ09B0327-0400
8.12.4 MOS Input Pull-Up Function
Port B 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 modes 1, 2 and 3 (EXPE = 1) with the ABW bit in WSCR
set to 1, and in modes 2 and 3 (EXPE = 0), and can be specified as on or off on a bit-by-bit basis.
When a PBDDR bit is cleared to 0, setting the corresponding PBODR bit to 1 turns on the MOS
input pull-up for that pin. When a pin is designated as an on-chip supporting module output pin,
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 8.27 summarizes the MOS input pull-up states.
Table 8.27 MOS Input Pull-Up States (Port B)
Mode Reset
Hardware
Standby Mode
Software
Standby Mode
In Other
Operations
1, 2, 3 (EXPE = 1) with
ABW in WSCR = 0
Off Off Off Off
1, 2, 3 (EXPE = 1) with
ABW in WSCR = 1, and
2, 3 (EXPE = 0)
On/Off On/Off
Legend:
Off: MOS input pull-up is always off.
On/Off:On when PBDDR = 0 and PBODR = 1; otherwise off.