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 address + 0C Read/Write 32-bit
Base Address Register Base address + 1C Read/Write 32-bit
Device Address Register Base address + 14 Read/Write 32-bit
Transfer Count Registers
Memory Transfer Counter Base address + 0A Read/Write 16-bit
Base Transfer Counter Base address + 1A Read/Write 16-bit
Function Code Registers
Memory Function Code Base address + 29 Read/Write 8-bit
Base Function Code Base address + 39 Read/Write 8-bit
Device Function Code Base address + 31 Read/Write 8-bit
Device Control Register Base address + 04 Read/Write 8-bit
Operation Control Register Base address + 05 Read/Write 8-bit
Sequence Control Register Base address + 06 Read/Write 8-bit
Channel Control Register Base address + 07 Read/Write 8-bit
Channel Status Register Base address + 00 Read/Write 8-bit
Channel Error Register Base address + 01 Read Only 8-bit
Channel Priority Register Base address + 2D Read/Write 8-bit
General Control Register Base address + FF Read/Write 8-bit
Interrupt Vector Registers
Normal Interrupt Vector Base address + 25 Read/Write 8-bit
Error Interrupt Vector Base address + 27 Read/Write 8-bit
Configuration Register Group:
Configuration Register 1 Base address + 101 Write Only 8-bit
Configuration Register 2 Base address + 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 µPD7210 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.