Port Control Register B (Pctrb) - Hitachi SH7750 Hardware Manual

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:
Initial value:
R/W:
Bit:
Initial value:
R/W:
Bit:
Initial value:
R/W:
Bit:
PB19PUP PB19IO PB18PUP PB18IO PB17PUP PB17IO PB16PUP PB16IO
Initial value:
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
Rev. 6.0, 07/02, page 744 of 986
31 30 29
— —
0 0
R R
23 22 21
— —
0 0
R R
15 14 13
— —
0 0
R R
7 6
0 0
R/W R/W R/W
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
28 27
— — —
0 0 0
R R R
20 19
— — —
0 0 0
R R R
12 11
— — —
0 0 0
R R R
5 4 3
0 0 0
R/W R/W
26 25 24
— —
0 0
R R
18 17 16
— —
0 0
R R
10 9
— —
0 0
R R
2 1
0 0
R/W R/W R/W
(Initial value)
—
0
R
—
0
R
8
—
0
R
0
0