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HD6417751 Datasheet, PDF (760/1105 Pages) Renesas Technology Corp – SuperH RISC engine
Bit 2n (n = 0–15)—Port I/O Control (PBnIO): Specifies whether each bit in the 16-bit port A is
an input or an output.
Bit 2n: PBnIO
0
1
Description
Bit m (m = 0–15) of 16-bit port A is an input
Bit m (m = 0–15) of 16-bit port A 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 A. 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.
PDTR 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
PB15DT PB14DT PB13DT PB12DT PB11DT PB10DT PB9DT
Initial value: —
—
—
—
—
—
—
R/W: R/W
R/W
R/W
R/W
R/W
R/W
R/W
8
PB8DT
—
R/W
Bit:
Initial value:
R/W:
7
PB7DT
—
R/W
6
PB6DT
—
R/W
5
PB5DT
—
R/W
4
PB4DT
—
R/W
3
PB3DT
—
R/W
2
PB2DT
—
R/W
1
PB1DT
—
R/W
0
PB0DT
—
R/W
18.2.3 Port Control Register B (PCTRB)
Port control register B (PCTRB) is a 32-bit readable/writable register that controls the input/output
direction and pull-up for each bit in the 16-bit port B (port 31 pin to port 16 pin). As the initial
value of port data register B (PDTRB) is undefined, each bit in the 16-bit port B should be set to
output with PCTRB after writing a value to the PDTRB register.
PCTRB is initialized to H'00000000 by a power-on reset. It is not initialized by a manual reset or
in standby mode, and retains its contents.
Rev. 3.0, 04/02, page 720 of 1064