GENERAL DESCRIPTION

The Z86C21 microcontroller is a member of the Z8 single-chip microcontroller family with 8 Kbytes of ROM and 236 bytes of RAM. The device is packaged in a 40-pin DIP, 44-pin PLCC, or a 44-pin QFP with a ROMless pin option available on the 44-pin versions only. With the ROM/ROMless feature selectively, the Z86C21 offers both external memory and preprogrammed ROM, making it wellsuited for high-volume applications or where code flexibility is required.

FEATURES

■ 8-Bit CMOS MCU with 8 Kbytes of ROM

■ 256 Byte Register File

- 236 Bytes of General-Purpose RAM

- 16 Bytes Control/Status Registers

- 4 Bytes for Ports

■ 40-Pin DIP, 44-Pin PLCC or 44-Pin QFP Package

■ 4.5V to 5.5V Operating Range

■ Low Power Consumption: 220 mW (max) @ 16 MHz

■ Fast instruction pointer: 1.0 µs @ 12 MHz

■ Two Standby Modes: STOP and HALT

■ 32 Input/Output Lines

FEATURES

■ Full-Duplex UART

■ All Digital Inputs are TTL Levels

■ Auto Latches

■ RAM and ROM Protect

■ Two Programmable 8-Bit Counter/Timers each with

6-Bit Programmable Prescaler.

■ Six Vectored, Priority Interrupts from Eight Different

Sources

■ Clock Speeds: 12 and 16 MHz

■ On-Chip Oscillator that Accepts a Crystal, Ceramic

Resonator, LC, or External Clock Drive.