ATMEL AT89SXX ISP Flash Programmer v1.3 Amit Sengupta,   amitsenxbabu@yahoo.com     [ Delhi    Mb : +91-9899526043 ] Introduction   ( Last Update  06/11/2007 ) Welcome to the word of Microcontrollers, and the first thing you need is a Device Programmer. This In System Programmer is RS232 (serial port) based but can indirectly be used with USB using USB to RS232 converter. If you need something like this you need to assemble a very simple circuit (Programmer Unit). Hardware Figure 1 shows  the  Block diagram of the in-system programmer interface,  the programmer can be self powered or target powered it depends on how you plan to use it. Figure 1:   Block Diagram of the ISP Programmer Figure 2  shows  the  actual circuit  diagram. The Programmer has just two ICs. IC1 = AT89C2051, IC2 = MAX 232. Few Resistors, LEDs, capacitors etc. The value of the crystal is critical and must be 11.0592 MHz.   Figure 2:   Circuit Diagram of the ISP Programmer Firmware. Assemble the circuit and burn the firmware into an AT89C2051(you will need a conventional parallel Programmer to Program the AT89C2051). Software The Software is a Windows GUI application and supports all programming functions. When you run the software for the first time it looks for a valid programmer on COM1. If the Programmer is connected to say COM2 you will receive an error message but when the application starts select Options->Settings on the Menu and specify the correct COM Port. Following are the main features of this software, Device Supported - AT89S51, AT89S52, AT89S8252, AT89S8253. Read and write  Intel Hex files. Chip Erase. Verify. Lock. Read Device Signature. Advanced Device Specific Functions. Download AT89S52 ISP Flash Programmer Software   ISP_PROG v1.3.zip Firmware for AT89C2051             Firmware v1.3.zip. Any feedback or suggestions to:  amitsenxbabu@yahoo.com                                                                                   ISP_PROG v1.3 Screen Shot                                                                  (C) Copyright 1997 - 2008 by Vault Information Services LLC. All Rights Reserved. Information provided "as-is" without warranty. Please see details. Contact us for usage and copy permission.