UPD8021

NEe Microcomputers, Inc. NEe ILPD8021 SINGLE CHIP 8·BIT MICROCOMPUTER DESCRIPTION The NECIlPD8021 is a stand alone 8-bit parallel microcomputer incorporating the following features usually found in external peripherals. The IlPD8021 contains: 1K x 8 bits of mask ROM program memory, 64 x 8 bits of RAM data memory, 21 I/O lines, an B-bit interval timer/event counter, and internal clock circuitry. FEATURES 8-Bit Processor, ROM, RAM, I/O, Timer/Counter Single +5V Supply (+4.5V to +6.5V) NMOS Silicon Gate Technology 8.381ls Instruction Cycle Time All Instructions 1 or 2 Cycles Instructions are Subset of IlPD8048/8748/8035 High Current Drive Capability - 2 I/O Pins Clock Generation Using Crystal or Single Inductor Zero-Cross Detection Capabil ity Expandable I/O Using 1l8243's Available in 28 Pin Plastic Package PIN CONFIGURATION Pn P23 PROG PO~ P01 P02 P03 P04 P07 ALE T1 VSS JlPD 8021 vee P21 26 P20 25 P17 24 P16 23 P15 22 P14 21 P13 20...