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PC Elite Reference
controls the state of the IEEE lines through the 7210 chip. This
chip does not connect directly to the IEEE lines but is buffered
through two IEEE line drivers that provide the correct signal
levels and line matching. The line drivers used are the Texas
Instruments SN75160 and SN75162 IEEE driver chips. These
drivers control the IEEE data and IEEE line management
respectively. The operation of these devices is described in the
device data book, "The Texas Instruments Interface Circuits Data
Book." The SN75160 and SN75162 line drivers are manipulated
using five control lines, TE and PE for the 75160 and TE, DC
and SC for the 75162. All but SC are driven by the 7210 chip.
The Elite card contains 4, large gate count, custom
programmable logic devices, P.L.D.'s. The P.L.D.'s determine
the i/o address of the 7210 chip in the PC's address space, the
setting of SC, the system controller line, of the Texas
Instruments 75162 GPIB management chip, the enabling and
disabling of the DMA and IRQ lines, the clearing of the IRQ
line and the sharing of the DMA and IRQ lines. Much of the
information about the 7210 chip in this chapter is taken from the
NEC data sheet and is copyright NEC.
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The NEC 7210 Chip.
The 7210 TLC is an intelligent GPIB interface controller
designed to meet all of the functional requirements for Talkers,
Listeners and Controllers as specified by the IEEE Standard 488-
1975. Connected between a processor bus and the GPIB, the
TLC provides high level managements of the GPIB to unburden
the processor and to simplify both hardware and software design.
Fully compatible with most processor architectures, Bus Driver/
Receivers are the only additional components required to
implement any type of GPIB interface.
Data may be transferred either under program control or
via DMA using the TLC's DMA control facilities to further
reduce processor overhead. in addition to providing all control
and data lines necessary for a complete GPIB implementation,
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Technical Details
Chapter 3
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