INS8238 Datasheet | National Semiconductor

Description The INS8228/INS8238 is a system controller/bus driver contained in a standard, 28-pin dual-in-line package. The chip, which is fabricated using Schottky Bipolar technology, generates all the read and write control signals required to directly interface the memory and input/output ponents of National Semiconductor's INS8080A microputer family. The chip also provides drive and isolation for the bidirectional data bus of the INS8080A microprocessor. Data bus 'isolation enables the use of slower memory and input/output ponents in a system, and provides for enhanced system noise immunity. A user-selected single-level interrupt vector (RST 7) is provided by the ch ip for use in the interrupt structure of small systems that need only one basic vector. No additional ponents (such as an interrupt instruction port) are required to use the single interrupt vector in these systems. The INS8228/1 NS8238 also generates an Interrupt Acknowledge (INTA) control signal for each byte of a multibyte CALL instruction when an interrupt is acknowledged by the INS8080A. This feature permits the use of a multifevel priority interrupt structure in large, interrupt-driven systems. Features - MICROBUSl M- patible - Single Chip System' Controller and Bus Driver for 1NS8080A Microputer Systems - Allows Use of Multibyte CALL Instructions for Interrupt Acknowledge - Provides User-Selected Single-Level Interrupt Vector (RST7) - Provides Isolation for Data Bus - Supports a Wide Variety of System Bus Structures - Reduces System ponent Count - INS8238 Provides Advanced Input/Output Write and Memory Write Control Signals for Large System Timing Control INS8080 Family CPU Group to MICROBUS Configuration INSBOSDA MICROPROC~SSij A ('. -C.MGDNAl NS TRO~L~ IWII,OB1N) IIl DA OJ-DO z en CD N (,.) -en 'e<n -(o") :::J Ca.-.D. m :::J Co m Cen C ::!. .C<.D. IIIHAFACE Vt VICE G~OUP r ERIPH<RAl CO~T~OL ~'I~E" '0 1 " > - - SP INS8Z5S: il1I'i - Trademark, National Semi.conductor Corp. © 1978...