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CHAPTER 3: Register Structure
3.0) Introduction
At the lowest level, the PC 62C can be programmed using I/O input and output
instructions. This chapter contains the information on all the PC 62C registers. Although
programming the board is not difficult, it is time consuming and requires detailed
knowledge of the PC 62C as well as the operation of the host PC and its operating
system. In order to simplify the process, a set of driver libraries is provided. The use of
these libraries allows access to all the board's functions and is described in Chapter 5:
Programming guide.
The PC 62C occupies 32 consecutive Word addresses in the computer's I/O space. The
layout of these registers is shown in Table 4: PC 62C Register Structure. The offset of
the registers is given as offset addresses from the base address of the board. This base
address is set with the DIP Switch as detailed in Chapter 2: Installation. It is important
that 16 bit reads and writes are initiated in order to minimize host CPU time. In
multitasking enviroments two 8 bit reads and writes will take much more host CPU time
than a single 16 bit read or write.
Offset
Read Write
0 Opto Isolator 0 Status (OPTORD0) Reserved
2 Global Status Register (GLOBAL) Global Status Register (GLOBAL)
4 Global Control Register (GLCNTRL) Global Control Register (GLCNTRL)
6 IRQ Gate Control Register (IGATE) IRQ Gate Control Register (IGATE)
8 Global Buffer Status Register (GBUF) Reserved
10 Local Mux IRQ Register 0 (IMUXP0) Local Mux IRQ Register 0 (IMUXP0)
12 Local Mux IRQ Register 1 (IMUXP1) Local Mux IRQ Register 1 (IMUXP1)
14 Local Mux IRQ Register 2 (IMUXP2) Local Mux IRQ Register 2 (IMUXP2)
16 Reserved Reserved
18 IRQ Set/Reset Status Register (ISETX) Interrupt Set/Reset Register (ISETX)
20 Digital I/O Read Register (DIO) Digital I/O Write Register (DIO)
22 Opto Isolator 1 Status (OPTORD1) Reserved
24 Opto Isolator 2 Status (OPTORD2) Reserved
26 Opto Isolator 3 Status (OPTORD3) Reserved
28 Reserved Reserved
30 Reserved Reserved
Reserved Reserved
Table 4: PC 62C Register Structure
