The STD8085 is the 8 bit microprocessor IP core, which may be used as replacement of 8085 processor device. Its software and cycle compatibility with industry standard, allows to use STD8085 in old projects, where 8085 devices are used.
The IP core is fully synchronous, one clock edge design. Compatibility to original device has been confirmed by direct, pin-to-pin comparison to original chip. Test environment diagram is shown on the picture below.Test environment diagram
Watch YouTube video example about replacing old 8085 processor with STD8085 implemented on FPGA:
Main control - This module decodes opcodes and controls execution of each instruction. It also controls serial input and output.
ALU - Arithmetic Logic Unit. It performs operations like adding, substracting, logic AND, OR, XOR, shifts, etc.
Memory control - Controls memory and I/O access. Ensures correct timming compatible with legacy standard.
Clock control - This unit is used for generating internal clock for cycle compatibility.
Interrupt control - Controls interrupt events and priorities.
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