SH7014 Datasheet, PDF (513/754 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer

17. I/O Ports (I/O)
17.3.2 Port B Data Register (PBDR)
Bit: 15
14
13
12
11
10
9
8
⎯
⎯
⎯
⎯
⎯
⎯ PB9DR PB8DR
Initial value: 0
0
0
0
0
0
0
0
R/W: R
R
R
R
R
R
R/W R/W
Bit: 7
6
5
4
3
2
1
0
PB7DR PB6DR PB5DR PB4DR PB3DR PB2DR PB1DR PB0DR
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*
Note: * R only in the SH7014.
PBDR is a 16-bit read/write register that stores data for port B. The bits PB9DR to PB0DR
correspond to the PB9/IRQ7/A21 to PB0/A16 pins. When the pins are used as ordinary outputs,
they will output whatever value is written in the PBDR; when PBDR is read, the register value
will be read regardless of the pin status. When the pins are used as ordinary inputs, the pin status
rather than the register value is read directly when PBDR is read. When a value is written to
PBDR, that value can be written into PBDR, but it will not affect the pin status. table 17.6 shows
the read/write operations of the port B data register.
PBDR is initialized by an external power-on reset. However, PBDR is not initialized for a reset by
WDT, standby mode, or sleep mode.
The settings of bits 1 and 0 of this register are functional only in the SH7016 and SH7017. In the
SH7014, there are no pins corresponding to these bits; they are always read as 0, and their write
value should always be 0.
Table 17.6 Read/Write Operation of the Port B Data Register (PBDR)
PBIOR
0
1
Pin Status
Ordinary input
Other function
Ordinary output
Other function
Read
Pin status
Pin status
PBDR value
PBDR value
Write
Can write to PBDR, but it has no effect on pin status
Can write to PBDR, but it has no effect on pin status
Value written is output by pin
Can write to PBDR, but it has no effect on pin status
Rev.5.00 Sep. 27, 2007 Page 479 of 716
REJ09B0398-0500