Register Bit Descriptions
Chapter 4
GPIB-1014 User Manual
4-2
© National Instruments Corporation
Table 4-1. GPIB-1014 Register Map (continued)
Register Name
Address (Hex)
Type
Size
DMA Register Group:
Address Registers
Memory Address Register
Base a 0C
Read/Write
32-bit
Base Address Register
Base a 1C
Read/Write
32-bit
Device Address Register
Base a 14
Read/Write
32-bit
Transfer Count Registers
Memory Transfer Counter
Base a 0A
Read/Write
16-bit
Base Transfer Counter
Base a 1A
Read/Write
16-bit
Function Code Registers
Memory Function Code
Base a 29
Read/Write
8-bit
Base Function Code
Base a 39
Read/Write
8-bit
Device Function Code
Base a 31
Read/Write
8-bit
Device Control Register
Base a 04
Read/Write
8-bit
Operation Control Register
Base a 05
Read/Write
8-bit
Sequence Control Register
Base a 06
Read/Write
8-bit
Channel Control Register
Base a 07
Read/Write
8-bit
Channel Status Register
Base a 00
Read/Write
8-bit
Channel Error Register
Base a 01
Read Only
8-bit
Channel Priority Register
Base a 2D
Read/Write
8-bit
General Control Register
Base a FF
Read/Write
8-bit
Interrupt Vector Registers
Normal Interrupt Vector
Base a 25
Read/Write
8-bit
Error Interrupt Vector
Base a 27
Read/Write
8-bit
Configuration Register Group:
Configuration Register 1
Base a 101
Write Only
8-bit
Configuration Register 2
Base a 105
Write Only
8-bit
Register Sizes
VMEbus computers support three transfer sizes for read and write operations: 8-, 16-, or 32-bit.
Table 4-1 shows the size of each GPIB-1014 register. For example, reading the Memory
Transfer Counter Register requires a 16-bit read operation at the indicated address, whereas
writing to the End Of String Register requires an 8-bit write operation at the indicated address.
Register Description
Table 4-1 divides the GPIB-1014 registers into three different register groups. A detailed bit
description of each of the registers making up these groups is included later in this chapter.
The GPIB Interface Register Group consists of 21 registers located in the NEC
µ
PD7210 TLC
chip. The DMA Register Group consists of 18 registers located in the 68450 DMAC chip. The
Configuration Register Group contains two registers used to configure some of the board
operating parameters.