Bit 2n + 1 (n = 0–15)—Port Pull-Up Control (PBnPUP): Specifies whether each bit in the 16-
bit port is to be pulled up with a built-in resistor. Pull-up is automatically turned off for a port pin
set to output by bit PBnIO.
Bit 2n + 1: PBnPUP
Description
0
1
Bit m (m = 0–15) of 16-bit port is pulled up
Bit m (m = 0–15) of 16-bit port is not pulled up
(Initial value)
Bit 2n (n = 0–15)—Port I/O Control (PBnIO): Specifies whether each bit in the 16-bit port is an
input or an output.
Bit 2n: PBnIO
Description
0
1
Bit m (m = 0–15) of 16-bit port is an input
Bit m (m = 0–15) of 16-bit port is an output
(Initial value)
18.2.2 Port Data Register A (PDTRA)
Port data register A (PDTRA) is a 16-bit readable/writable register used as a data latch for each bit
in the 16-bit port. When a bit is set as an output, the value written to the PDTRA register is output
from the external pin. When a value is read from the PDTRA register while a bit is set as an input,
the external pin value sampled on the external bus clock is read. When a bit is set as an output, the
value written to the PDTRA register is read.
PDTRA is not initialized by a power-on or manual reset, or in standby mode, and retains its
contents.
Bit:
15
14
13
12
11
10
9
8
PB15DT PB14DT PB13DT PB12DT PB11DT PB10DT PB9DT PB8DT
Initial value:
R/W:
—
—
—
—
—
—
—
—
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Bit:
7
6
5
4
3
2
1
0
PB7DT PB6DT PB5DT PB4DT PB3DT PB2DT PB1DT PB0DT
Initial value:
R/W:
—
—
—
—
—
—
—
—
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Rev. 6.0, 07/02, page 743 of 986
RENESAS [ RENESAS TECHNOLOGY CORP ]
