Chapter 4 Register Descriptions
© National Instruments Corporation 4-65 GPIB-1014 User Manual
Bit Mnemonic Description
4-3w BRG Bus Request/Grant Bits
The Bus Request/Grant bits are used to select which pair of the
VMEbus request/grant lines are used by the GPIB-1014 to request and
obtain control of the system bus.
00 = BR0*/BG0IN*-BG0OUT* selected
01 = BR1*/BG1IN*-BG1OUT* selected
10 = BR2*/BG2IN*-BG2OUT* selected
11 = BR3*/BG3IN*-BG3OUT* selected
BR0*/BG0IN*-BG0OUT* is selected automatically after power-up or
after the board is reset.
2w CC Carry Cycle Bit
The Carry Cycle bit is used to enable or disable the automatic carry
cycle feature of the GPIB-1014.
1 = Carry Cycle feature enabled
0 = Carry Cycle feature disabled
The feature is not enabled after power-up or after the board is reset.
1w ROR* Release On Request Bit
The Release On Request bit is used to indicate the status of the Release
On Request feature for the GPIB-1014.
1 = Release On Request feature disabled
0 = Release On Request feature enabled
The feature is automatically disabled (ROR=1) after power-up or after
the board is reset.
0w DIR Direction Bit
This bit is used to indicate the direction of the GPIB DMA data
transfer.
0 = Transfer from system memory to GPIB
1 = Transfer from GPIB to system memory
This bit is cleared to 0 (transfer from system memory to GPIB) after
power-up or reset.