INTRODUCTION
Now this is another kind of design but use a minimum system types using Atmel MCS51 S-series with ISP programming. So with this kind of board, the chip do not need to remove just programmed on board. Programed using ISP programming could be done directly through LPT parallel port. There are many programming software could be found on the internet. Some that I could find and much realiable eq.: AEC-ISP programmer, this kind is DOS version. Could be download at : AEC-Electronics. Also ISP programmer made by Asim Khan, could be download at : Asim Khan's ISP software, this kind is a windows version. Besides that there is software from Adam Dybkowsky which run both version of programmers. It could be found at : Adam's Home Page ISP PROG ATMEL89Sxx. Every programmers used its own ISP cable.
There are many kinds of pin connections between these programmers, but I alredy tested for both of these 2 kinds of programmers. They are more reliable, among any kinds of LPT port from each computer. Some people succeeded while the other not. Some of them suggested using an IC buffer to interface the LPT parallel port, but I tested it with direct cable connection. It doesn't matter, all can run smoothly. For AEC ISP cable, the connection could be found from the software itself or from Ibrahim Kamal design. Asim Khan ISP PGM cable could be found at : cheap Loader Cable of Asim's ISP for 89S51/89S52, Adam's programmer could be use any kind of cables connections, include for both of those cables. But I did not test all of the connections. Asim's ISP PGM cable is the same as SI Prog cable option. Both of these cable connection (AEC-ISP cable and ISP-PGM cable) could be run on this software. Some people made these cable connections and tested at their own computer with bad result, while some people were succeed. There was another kind of cable connection. I found it at : mytutorialcafe.com, for using with Atmel ISP programmer software. But I could not run it well on my computers. I think that both AEC-ISP cable and ISP-PGM cable are the most reliable cable connection for any other kind of LPT parallel port from many computers
In System Programming (ISP)
What is an ISP programming?
This kind of explanation I took from IKA web site :
ISP is a way to serially program your micro controller, while it resides in its place, in other words, without removing the chip from your board. Whether you're just starting in the ATMEL micro controllers, or you're familiar with it, ISP (In System Programming) will provide you a simple and affordable home made solution to program and debug your micro controller based project. ATMEL release some of their product with these ISP programming, the chips sign with S-type, like AT89S51, AT89S52, etc.
Normally, the flash memory of an ATMEL micro controller is programmed using a parallel interface, which consists of sending the data byte by byte (using 8 independent lines for the data, and another bunch of lines for the address, the control word and clock input). On the other hand ISP is performed using only 4 lines, and literally, data is transferred through 2 lines only, as in a I2C interface, where data is shifted in bit by bit though. MOSI line, with a clock cycle between each bit and the next (on the SCK line). MISO line is used for reading and for code verification, it is only used to output the code from the FLASH memory of the micro controller. The RST pin, which is normally used to reset the device, is also used to enable the 3 pins (MOSI, MISO and SCK) to be used for ISP simply by setting RST to HIGH (5V), otherwise if RST is low (0V), your program start running and those three pins, are used normally as P1.5, P1.6 and P1.7.
Here is ISP Programming sequence as described in ATMEL datasheets:
"The Code memory array can be programmed using the serial ISP interface while RST is pulled to VCC. The serial interface consists of pins SCK, MOSI (input) and MISO (output). After RST is set high, the Programming Enable instruction needs to be executed first before other operations can be executed. Before a reprogramming sequence can occur, a Chip Erase operation isrequired.
The Chip Erase operation turns the content of every memory location in the Code array into FFH.
Either an external system clock can be supplied at pin XTAL1 or a crystal needs to be connected across pins XTAL1 and XTAL2. The maximum serial clock (SCK) frequency should be less than 1/16 of the crystal frequency. With a 33 MHz oscillator clock, the maximum SCK frequency is 2 MHz. "
Download :
schematic board
PCB design