HD6417750 Datasheet, PDF (796/1039 Pages) Renesas Technology Corp – SuperH RISC engine

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 4-bit port (port 19 pin to port 16 pin). As the initial value
of port data register B (PDTRB) is undefined, each bit in the 4-bit port 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.
Bit: 31
30
29
28
27
26
25
24
—
—
—
—
—
—
—
—
Initial value: 0
0
0
0
0
0
0
0
R/W: R
R
R
R
R
R
R
R
Bit: 23
22
21
20
19
18
17
16
—
—
—
—
—
—
—
—
Initial value: 0
0
0
0
0
0
0
0
R/W: R
R
R
R
R
R
R
R
Bit: 15
14
13
12
11
10
9
8
—
—
—
—
—
—
—
—
Initial value: 0
0
0
0
0
0
0
0
R/W: R
R
R
R
R
R
R
R
Bit: 7
6
5
4
3
2
1
0
PB19PUP PB19IO PB18PUP PB18IO PB17PUP PB17IO PB16PUP PB16IO
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
Bit 2n + 1 (n = 0–3)—Port Pull-Up Control (PBnPUP): Specifies whether each bit in the 4-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
0
1
Description
Bit m (m = 16–19) of 4-bit port is pulled up
Bit m (m = 16–19) of 4-bit port is not pulled up
(Initial value)
Rev. 6.0, 07/02, page 744 of 986