
HITACHI 418
15.3.2
Port B Data Register (PBDR)
PBDR is a 16-bit read/write register that stores data for port B. The bits PB15DR–PB0DR
correspond to the PB15/TP15/
IRQ7
–PB0/TP0/TIOCA2 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 output 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. When the pin
function is set to timing pattern output and the TPC output is enabled by the TPC next data enable
register (NDER), no value can be written to PBDR. Table 15.4 shows the read/write operations of
the port B data register.
PBDR is initialized by a power-on reset. However, PBDR is not initialized for a manual reset,
standby mode, or sleep mode.
Bit:
15
14
13
12
11
10
9
8
Bit name:
PB15DR PB14DR PB13DR PB12DR PB11DR PB10DR PB9DR
PB8DR
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:
7
6
5
4
3
2
1
0
Bit name:
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
Table 15.4
Read/Write Operation of the Port B Data Register (PBDR)
PBIOR
Pin Status
Read
Write
0
Input
Pin status
Can write to PBDR, but it has no effect on pin
status
TPn
Pin status
Disabled
Other function
Pin status
Can write to PBDR, but it has no effect on pin
status
1
Output
PBDR value
Value written is output by pin
TPn
PBDR value
Disabled
Other function
PBDR value
Can write to PBDR, but it has no effect on pin
status
TPn: Timing pattern output