HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 427

• Manufacturer Part Number: HD6417021
• Description: SuperH RISC engine
• Manufacturer: Hitachi Semiconductor

Table 15.1 Port A Register
Name
Port A data register
15.2.2
PADR is a 16-bit read/write register that stores data for port A. The bits PA15DR–PA0DR
correspond to the PA15/IRQ3/DREQ1–PA0/CS4/TIOCA0 pins. When the pins are used as
ordinary outputs, they will output whatever value is written in the PADR; when PADR 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 PADR is read. When a
value is written to PADR, that value can be written into PADR, but it will not affect the pin status.
Table 15.2 shows the read/write operations of the port A data register.
PADR is initialized by a power-on reset. However, PADR is not initialized for manual reset,
standby mode, or sleep mode.
Table 15.2 Read/Write Operation of the Port A Data Register (PADR)
PAIOR
0
1
HITACHI 416
Initial value:
Initial value:
Bit name:
Bit name:
Port A Data Register (PADR)
Pin Status
Input
Other function
Output
Other function
R/W:
R/W:
Bit:
Bit:
PA15DR PA14DR PA13DR PA12DR PA11DR PA10DR PA9DR PA8DR
PA7DR PA6DR
Abbreviation
PADR
R/W
R/W
15
0
7
0
Read
Pin status
Pin status
PADR value
PADR value
R/W
R/W
14
0
6
0
R/W
R/W
PA5DR PA4DR
R/W
R/W
13
0
5
0
Write
Can write to PADR, but it has no effect on pin
status.
Can write to PADR, but it has no effect on pin
status.
Value written is output by pin
Can write to PADR, but it has no effect on pin
status.
Initial Value
H'0000
R/W
R/W
12
4
0
0
PA3DR
R/W
R/W
11
0
3
0
Address
H'5FFFFC0
PA2DR PA1DR
R/W
R/W
10
0
2
0
Access Size
8, 16, 32
R/W
R/W
1
0
9
0
PA0DR
R/W
R/W
8
0
0
0