8255 Data Registers - Advantech PCM-3724 User Manual

3.2.3 8255 Data Registers

The PCM-3724's I/O ports (BASE+0 to 2 and BASE+4 to 6) directly map
to the 8255 ports. Bits assignments for each I/O port appear below:
BASE+0 8255 Port A0 (read/write)
Bit 7
Value PA07
BASE+1 8255 Port B0 (read/write)
Bit 7
Value PB07
BASE+2 8255 Port C0 (read/write)
Bit 7
Value PC07
BASE+4 8255 Port A1 (read/write)
Bit 7
Value PA17
BASE+5 8255 Port B1 (read/write)
Bit 7
Value PB17
BASE+6 8255 Port C1 (read/write)
Bit 7
Value PC17
PCM-3724 User Manual
6 5
PA06 PA05
6 5
PB06 PB05 PB04
6 5
PC06 PC05 PC04
6 5
PA16 PA15
6 5
PB16 PB15 PB14
6 5
PC16 PC15 PC14
4 3
PA04 PA03
4 3
PB03
4 3
PC03
4 3
PA14 PA13
4 3
PB13
4 3
PC13
18
2 1 0
PA02 PA01 PA00
2 1 0
PB02 PB01 PB00
2 1 0
PC02 PC01 PC00
2 1 0
PA12 PA11 PA10
2 1 0
PB12 PB11 PB10
2 1 0
PC12 PC11 PC10