Description

The TNT4882 provides a single-chip IEEE 488.2 Talker/Listener interface to the general-purpose interface bus (GPIB). The TNT4882 combines the circuitry of the NAT4882 IEEE 488.2 application-specific integrated circuit (ASIC), Turbo488 performance-enhancing ASIC, and GPIB transceivers to create a single-chip IEEE 488.2 interface. Because the TNT4882 contains the NAT4882 register set, which in turn has the NEC µPD7210 and TI TMS 9914A register sets, developers using any of these chips can easily port existing code directly to the TNT4882, thereby significantly reducing software development time. Also, with just a few modifications, you can implement all the improved features of the IEEE 488.2 standard. The TNT4882 is ideal for use in all IEEE 488 instrument designs because of its small size, surface-mount ability, and performance enhancements that include HS488, a new high-speed mode for GPIB transfers.

Features

100-pin plastic quad flat pack (QFP), surface

mount package

IEEE 488.1-compatible transceivers on chip

Fast data transfers

– Up to 1.5 Mbytes/s using interlocked

IEEE 488.1 handshake

– Up to 8 Mbytes/s using HS488™

Two 8-bit 16-deep FIFOs buffer data

between GPIB and CPU

With exception of Controller, performs all

IEEE 488 interface functions

– SH1, AH1, T5 or TE5, L3 or LE3,

SR1, RL1, PP1 or PP2, DC1, DT1,

and C0

Meets all IEEE 488.2 requirements

– Bus line monitoring

– Preferred implementation of

requesting service

– Not sending messages when there are

no Listeners

Software compatible with

Turbo488™/NAT4882™ ASICs

Reduces software overhead

– Does not lose a data byte if ATN is

asserted while transmitting data

– Static interrupts status bits that do

not clear when read

– Automatically transmits END or

performs RFD holdoff on last byte

of DMA transfer

– Interrupts when handshake is

complete on last byte of a DMA

transfer

– Has 32-bit counter for large,

uninterrupted data transfers

Programmable timer interrupt for

general-purpose timing use

Complete in-system functional testing

with internal loop-back mode

ISA bus glue logic on chip

Direct memory access (DMA)

Device status indicator pins

– My Address, Talk Addressed, Listen

Addressed, REM, DCAS, TRIG

Automatically processes IEEE 488

commands and reads undefined

commands

Handles 6 primary and secondary

addressing modes

Automatic EOS and/or NL message

detection

Programmable data transfer rate –

TTL-compatible CMOS device