TK87C749 Microcontroller

General Description

Based on the TK80C51, the TK87C749 is economically priced and comes in a small package size. Tekmos uses high-density CMOS technology to construct the TK87C749 Microcontroller, decreasing CMOS latch-up sensitivity through epitaxial substrate.

The TK87C749 contains a 64k x 8 Flash, a 256 x 8 RAM, 21 I/O lines, a 16-bit auto-reload counter/timer, a fixed-priority level interrupt structure, an on-chip oscillator, a five channel multiplexed 8-bit A/D converter, and an 8-bit PWM output. Additionally, the device comes with two power-reduction modes: idle and power down.

The TK87C749 is a derivative of the 8051 microcontroller architecture. With 64Kx8 of Flash ROM, and 128x8 of scratchpad RAM, this part is a pin-for-pin replacement of the NXP 87C749 microcontroller.

The TK87C749 is intended to provide the 80C51 architecture in a small package and with both an 8-bit ADC and an 8-bit PWM capability.

To achieve this, port P2, and 3 bits of port P0 were removed, along with the external bus control pins.  This allows the TK87C751 to fit within either a 28 pin, 300 mil PDIP package, or a 28 pin PLCC package.

The ability of the design to access external program and data memory was also removed, along with the PSEN, ALE, and EA pins.

Because the TK87C749 utilizes a Flash ROM, it may be re-programmed if required. The original part was a One-Time-Programmable (OTP) part. 

Features