UPD556

NEe Microcomputers, Inc. NEe fLPD556 EVACHIP·43 DESCR IPTION The IlPD556 is an evaluation chip for the IlCOM-43/44/45 single chip microcomputers_ Designed to be used for both hardware and software debugging, the EVACH IP-43 is functionally equivalent to the IlCOM-43, except that it does not contain on-chip ROM. Instead, it is able to address external memory. In addition, in order to facilitate debugging, the IlPD556 is capable of displaying the contents of the internal accumulator and data pointer and of being single stepped. When the IlPD556 is being used to evaluate IlCOM-44/45 designs, the external memory capacity should be restricted to that of the respective.on-chip ROM and the instructions should be restricted to the 58 comprising the IlCOM-44/45 instruction set. FEATU RES 4-bit Parallel Processor Full 80 Instruction Set of IlCOM-43 lOlls Instruction Cycle Capable of addressing 2K x B-bits of external program memory Single step capability Full Func...