SETTING SYSTEM FOR DATA PRESCRIBING LSI WORKING RANGE

摘要

PURPOSE:To set a large quantity of working range prescription data to an LSI just with occupation of a small number of LSI terminals by reading the LSI working range prescription data out of a ROM to prescribe the LSI in response to plural applications. CONSTITUTION:A ROM 2 storing the working range prescription data on an LSI 1 is connected to an address bus 3 and a data bus 4 connected with the LSI 1. The LSI 1 produces the head address of the LSI working range prescrip tion data stored in the ROM 2 form the value of a ROM address selection terminal of the LSI 1 and a fixed address in the LSI 1 after a reset terminal is activated and initially reset. Then the LSI 1 reads out autonomously the necessary number of words and at the same time sets the data read out succes sively to a working range prescription data register 19. Thus it is possible to set the working range of the LSI 1 within the LSI 1 itself just by occupying a terminal including a small number of IO addresses proper to the LSI 1. Furthermore an access to be given to the LSI 1 can be decided without using any external circuit.