Register format – ADLINK PCI-7256 User Manual
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16 • Register Format
3
Register Format
The detailed descriptions of the register format are specified in this chapter. 
This information is quite useful for the programmers who want to handle the 
card by low-level programming. However, we suggest user understand more 
about the PCI interface before starting low-level programming. 
3.1 I/O Address Map
The 7256 registers are all 16-bit wide. Users can access these registers only 
by 16 bits I/O instructions. The control of the relays and status of the 
isolation input is by means of accessing registers. The following table shows 
the register map, including descriptions and their offset addresses relative to 
the base address. 
Table 3.1 The register map of PCI-7256
Offset
Write
Read
0x00h
Relay Output CH. 0~7
--
0x02h
Relay Output CH. 8~15
Relay Output Read back
CH.0~15
0x04h
---
Isolated Input CH. 0~15
0x06h
COS Setup Register
COS Latch Register
0x08h
Interrupt Control Register
Interrupt Status Register