Chapter 2 General Description
© National Instruments Corporation 2-3 GPIB-1014 User Manual
to generate its board select signal. It then decodes the lowest eight lines, A8 through A1, to
address the following items:
• The 68450 DMA Controller (DMAC)
• The µPD7210 GPIB Talker/Listener/Controller (TLC)
• Two 8-bit, write-only Configuration Registers
You can configure the base address of the board through the hardware jumper set W1 located on
the interface board. Except for the models GPIB-1014-1S and GPIB-1014-1S-EH, the base
address can also be set using strapped address lines located on the VMEbus P2 connector. See
Chapter 3, Configuration and Installation, on how to set the base address of the board.
VMEbus Slave-Data
The GPIB-1014 can function as a VMEbus slave, decoding short I/O addresses and commands
from a VMEbus master. The µPD7210 and the two Configuration Registers function as 8-bit
slaves, allowing data to be transferred to and from the VMEbus Master on data lines D07
through D00. The 68450 can function as an 8- or 16-bit slave, allowing transfers on data lines
D15 through D00. The board is designed to accommodate Address Only (ADO) cycles. In
VMEbus terminology, the slave module of the board is designated as D16 & D08(EO).
The GPIB Interface Registers associated with the µPD7210 are addressed relative to the base
address of the board, as shown in Table 2-2. The DMA registers internal to the 68450 are shown
in Table 2-3. The two Configuration Registers of the GPIB-1014 are shown in Table 2-4.
Table 2-2. µPD7210 Internal GPIB Interface Registers
Address
(Base + Hex Offset) Mode Register Size
111 R Data In (DIR) 8 bits
111 W Command/Data Out (CDOR) 8 bits
113 R Interrupt Status 1 (ISR1) 8 bits
113 W Interrupt Mask 1 (IMR1) 8 bits
115 R Interrupt Status 2 (ISR2) 8 bits
115 W Interrupt Mask 2 (IMR2) 8 bits
117 R Serial Poll Status (SPSR) 8 bits
117 W Serial Poll Mode (SPMR) 8 bits
119 R Address Status (ADSR) 8 bits
119 W Address Mode (ADMR) 8 bits
11B R Command Pass Through (CPTR) 8 bits
11B W Auxiliary Mode (AUXMR) 8 bits
11D R Address 0 (ADR0) 8 bits
11D W Address (ADR) 8 bits
11F R Address 1 (ADR1) 8 bits
11F W End of String (EOSR) 8 bits