Register Descriptions; Port Control Register A (Pctra) - Hitachi SH7751 Hardware Manual

18.2

Register Descriptions

18.2.1

Port Control Register A (PCTRA)

Port control register A (PCTRA) is a 32-bit readable/writable register that controls the
input/output direction and pull-up for each bit in the 16-bit port A (port 15 pin to port 0 pin). As
the initial value of port data register A (PDTRA) is undefined, all the bits in the 16-bit port A
should be set to output with PCTRA after writing a value to the PDTRA register.
PCTRA 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
PB15PUP
Initial value: 0
R/W: R/W
Bit: 23
PB11PUP
Initial value: 0
R/W: R/W
Bit: 15
PB7PUP
Initial value: 0
R/W: R/W
Bit: 7
PB3PUP
Initial value: 0
R/W: R/W
Bit 2n + 1 (n = 0–15)—Port Pull-Up Control (PBnPUP): Specifies whether each bit in the 16-
bit port A 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
30 29
PB15IO PB14PUP
0 0
R/W R/W
22 21
PB11IO PB10PUP
0 0
R/W R/W
14 13
PB7IO PB6PUP
0 0
R/W R/W
6 5
PB3IO PB2PUP
0 0
R/W R/W
Description
Bit m (m = 0–15) of 16-bit port A is pulled up
Bit m (m = 0–15) of 16-bit port A is not pulled up
28 27
PB14IO PB13PUP PB13IO
0 0
R/W R/W
20 19
PB10IO PB9PUP
0 0
R/W R/W
12 11
PB6IO PB5PUP
0 0
R/W R/W
4 3
PB2IO PB1PUP
0 0
R/W R/W
Rev. 3.0, 04/02, page 719 of 1064
26 25
PB12PUP PB12IO
0 0
R/W R/W
18 17
PB9IO PB8PUP PB8IO
0 0
R/W R/W
10 9
PB5IO PB4PUP PB4IO
0 0
R/W R/W
2 1
PB1IO PB0PUP PB0IO
0 0
R/W R/W
(Initial value)
24
0
R/W
16
0
R/W
8
0
R/W
0
0
R/W