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Low-level Programming
Chapter 3: Low-level Programming
A low-level programming interface of PCI-16P16R is
described in this chapter. If you wish to control the digital
input/output operations through the primitive I/O functions
(
inportb and outportb
), you have to be careful to understand
the meaning of the structure of the 8 registers. Here, you will
get all detailed information of the PCI-16P16R’s register
format and control procedures.
3.1 I/O Port Address Map
The PCI-16P16R requires 2 consecutive addresses in the PC
I/O address space. The following table (Table 3.1) shows the
location of each register and driver relative to the base
address and its description.
I/O Base
address
Read
Write
Base+00
Isolated inputs
(DI0~DI15)
Relay outputs
(R0~R15)
Base+02
Relay outputs
Status (Read
back)
Table 3.1: The location of register and driver
