General Description
Section Two
GPIB-1014P User Manual
2-2
© National Instruments Corporation
Table 2-1. GPIB-1014P Signals (continued)
Driver Device
Receiver Device
Bus Signals
Part Number
Part Number
DTACK*
F38
LS240
IACKOUT*
F20
–
IRQ1*through IRQ7*
F38
–
AS*,DS1*,WRITE*
–
ALS244
A03 through A01
–
ALS244
The GPIB transceivers meet the requirements of the IEEE-488 standard. The components used
are as follows:
Transceivers
Component Designation
Data Transceivers
75160
Control Transceivers
75162
Note: Current load is typically 0.5 A (1 A maximum).
VMEbus Characteristics
The following paragraphs describe both modules on the GPIB-1014P: slave and interrupter.
Table 2-3 later in this section summarizes the capabilities of these modules.
VMEbus Slave-Addressing
The GPIB-1014P occupies 16 bytes of consecutive memory addresses located in the A16 (short)
Input/Output (I/O) space. These addresses are used to access the GPIB Talker/Listener/Controller
(TLC). As a VMEbus slave, it only responds when the address modifier (AM) lines specify a
short supervisory access (AM code = 2D) or short non-privileged access (AM code = 29). An
onboard jumper allows selection of privileged or non-privileged access to the board.
The board responds to 16-bit addresses. It compares address lines A04 through A15 with its
hardware-programmable base address (see Base Address in Section Three) to generate its board
select signal. The Talker/Listener/Controller (TLC) decodes the remaining address lines, A01
through A03, and the data strobe DSO* into eight memory-mapped interface register addresses.
The GPIB TLC (
µ
PD7210) interface registers are addressed relative to the base address of the
board as shown in Table 2-2.