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You are here: 8051 Tools Development Board Old Versions Rev 3 (2001) Buying Parts

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Rev 4
New Rev 4 Board
A newer version (Rev 4) of this circuit board is available. Rev 4 includes a faster CPU, more memory, more I/O and an optional LCD. We recommend you use Rev 4 for new projects. Even though this older board is no longer available, we are keeping these old pages on-line for reference to assist people who purchased or build the older version.

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Rev 3 board are no longer available.

Rev 4

We are working on a new version of this 8051 development board. A small quantity of the new boards should be available by mid October, and we'll have plenty of them in November. (Rev 4 began shipping in November 2001.) The new board adds the following features:
  • 22.1184 MHz (twice the speed of rev 3) - This speed allows all standard baud rates, except 300 baud. Previously 57600 was the max. Now 115200 and 38400 will work. Note: 38400 or 19200 should be used when downloading to the flash rom... 115200 usually works, but it is faster than the worst-case flash write latency.
  • 32k SRAM, 24k usable for code download (rev 3 had 8k)
  • 30k Flash (rev 3 had 32k, but the top 2k is now used for I/O)
  • 50 I/O lines. Rev 3 had 34, and 8 were shared with the LEDs.
  • LEDs have dedicated I/O, not shared with any of the 50 I/O pins
  • LCD port... will have 16x2 LCD available that plugs into it for $10. This port is compatible with most character LCD that have a contoller chip like the HD44780 (industry standard for sizes up to 20x4). The board has a trim pot to adjust the LCD contrast. LCD pins are labeled on the board with names corresponding to LCD pinout of all common character displays (R/W, RS, E, Vee, etc).
  • Bus expansion signals available, all signals plus 4 chip selects (256 byte range for each). Rev 3 had only part of the address bus and 1 chip select available at the I/O connector edge. Because the 50 I/O lines fill the edge of the prototype area, the bus signals are on 34 pads in the center of the new board. All the pins are nicely labeled on the board.
  • Merged code/data space (previously only movc would read ram, now either movc or movx will read ram, flash, and I/O.) This change should allow Basic-52 programs to run, and at some point in the future I'm planning to make a port of Basic-52 that works nicely together with the monitor.
Rev 4 boards are available. Soon we should have some photos of the new board, and firm pricing. It is my goal to keep the price the same or similar as rev 3, but there are more parts on this new board. When we have an exact price for the new board, we'll put new ordering pages on-line, and ship the them in the order we receive them when the new boards are ready. (of course, we only bill your credit card on the day the package ships).

Development Board Items

Part Number Description Price
DEV_PCB_ASSEM 8051 Development Board, Fully Assembled and Tested. Rev 3: Unavailable
DEV_PCB_KIT 8051 Development Board, Complete Kit, Unassembled. Rev 3: Unavailable
DEV_PCB_BARE 8051 Development Board, Bare Circuit Board Rev 3: Unavailable
87C52_PM21_2F 87C52 Chip, Pre-programmed with PAULMON2 V2.1, Config for RAM at 0x2000, 39F512 Flash ROM at 0x8000 $15
39F512_DIP 39F512 Flash ROM Chip, 32 Pin DIP Package 32 pin DIP: Unavailable

Prices shown are in US dollars.

8051 Development System Circuit Board, Paul Stoffregen
Last updated: February 24, 2005
Status: finished
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