Retro

A page to show how easy STM32 and Forth makes embedded design in the 2020’s.

AT89C2051 MCU

This was a 8051 with on board 2KB flash, a couple of timer counters, a USART, comparator, what a great mcu in the 90’s. It was far, far easier than wiring up a cpu, ram, rom, timers, I/O etc.

_images/AT89C2051.jpg

Features

  • Compatible with MCS®-51Products

  • 2K Bytes of Reprogrammable Flash Memory, Endurance: 10,000 Write/Erase Cycles

  • 2.7V to 6V Operating Range

  • Fully Static Operation: 0 Hz to 24 MHz

  • Two-level Program Memory Lock

  • 128 x 8-bit Internal RAM

  • 15 Programmable I/O Lines

  • Two 16-bit Timer/Counters

  • Six Interrupt Sources

  • Programmable Serial UART Channel

  • Direct LED Drive Outputs

  • On-chip Analog Comparator

  • Low-power Idle and Power-down Modes

  • Green (Pb/Halide-free) Packaging Option

In Circuit Programmer

I had to design and make all this, just so I could program the chip in-circuit using a PC. I used SDCC, a FLOSS C compiler.

_images/burn-schematic.jpg