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
—
0
30
—
0
29
—
0
28
—
0
27
—
0
26
—
0
25
—
0
24
—
0
Initial value:
R/W:
R
R
R
R
R
R
R
R
Bit:
23
—
0
22
—
0
21
—
0
20
—
0
19
—
0
18
—
0
17
—
0
16
—
0
Initial value:
R/W:
R
R
R
R
R
R
R
R
Bit:
15
—
0
14
—
0
13
—
0
12
—
0
11
—
0
10
—
0
9
—
0
8
—
0
Initial value:
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:
R/W:
0
0
0
0
0
0
0
0
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
Description
0
1
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
RENESAS [ RENESAS TECHNOLOGY CORP ]
