Section Two
General Description
© National Instruments Corporation
2-9
GPIB-1014P User Manual
The interface consists of these major components which are discussed in greater detail in Section
Six.
•
VMEbus Interface
Consists of the buffers, drivers, and transceivers for
the address, data, status, and control lines used on the
VMEbus, plus other logic circuitry that converts
internal signals to bus-compatible signals.
•
Address Decoder
Recognizes when the VMEbus master addresses one
of the GPIB-1014P registers and generates the
appropriate strobe to effect the data transfer.
•
Clock and Reset Circuitry
Monitors the VMEbus utility signals to generate the 8
MHz clock used by the TLC and to detect System
Reset.
•
Timing State Machine
Controls the timing of accesses to the GPIB-1014P
from the VMEbus.
•
Interrupter
Implements the correct VMEbus priority interrupt
protocol, allowing the GPIB-1014P to request and
respond to an interrupt acknowledge cycle. All
interrupt conditions are also detectable by polling.
•
GPIB TLC (NEC
µ
PD7210)
Implements many of the GPIB interface functions,
either independently or with assistance of or
interpretation by the controlling program. Together
with special transceivers, the TLC forms the GPIB
interface side of the GPIB-1014P.