AT89C51 AT89S51 AT89C51RC AT89C1051U AT89C52 AT89S52 AT89C55WD AT89C2051 AT89C55 AT89S53 AT89S8252 AT89C4051

Note: For 20 pin devices a simple interface adapter is required. HardwareFigure 1 shows the circuit diagram of the Flash Programmer, the programmer is interfaced with the standard parallel port of the PC. As shown in the diagram U2 is used to control the data flow between the controller and the PC, U4 latched the low order address byte and U5 latched the high order address byte, while U3 is used to generate the control signals for micro controller to be programmed. IC U1 is used to generate the progrram pulse for the u-controller. The power supply section uses U8 to generate the logic 5V supply while the U7 is used to provide the programming supply voltage to controller. IC U6 is used to generate the VDD power supply voltage for the u-controller which is selectable either 5v or 6v5.

The power to the circuit is provided by a wall adapter of 15 to 18V output, normally a 15V type adapter will provide a 19~20V output voltage. As shown in the diagram the crystal X1 can be replaced by a resonator in that case capacitors C4 and C5 are not required. Place a small heatsink on U8 voltage regulator.

For the adjustment of P1, P2 and P3 use a digital multimeter & follow the steps shown below,

1. To adjust P1, temporarily connect T1 base to ground using test clips then adjust P1 to get 6.5V at the

output of regulator U6.

2. Next first adjust P2 to get the 13.1V at the output of regulator U7, make sure transistor T5 is off or

temporarily connect the T5 base to ground using test clips.

3. Now temporarily short the collector of transistor T5 to ground using test clips.

3. Adjust P3 to get the 12.1V at the output of U7 regulator IC.

Figure 1: Circuit Diagram of Flash Programmer V3.0

Figure 2 shows the circuit diagram of the interface adapter card required for the programming of 20 pin Flash devices.

Figure 2: Interface Adapter circuit diagram V3.0s Constructing the BoardThe prototype board may be built using universal PCB with point-to-point wiring. If you want to make your own PCB, download the PcbsPgm89v3.zip file which contains the printer files for the HP laser printer or download the PcbsPCX.zip file which contains PCX graphics format pcb files. Figure 3 shows the components layout of the programmer pcb.

For printing the PRN files on laser printer run the following command, this will print the all pcb files.

COPY *.PRN PRN/B

For the bill of material of the project view the file Pgm89v3PartsList.txt

The schematics and the pcbs of the project were designed using OrCAD softwar

Figure 3: Components layout of the Programmer PCB V3.0 SoftwarePgm89v3.zip file is used to run the programmer. This is a Windows program which can be used under

Windows 95 & 98. The main screen of the program is shown in figure 4.

Following are the main features of this software, Read and Write the Intel Hex File Read Chip info Clear, Fill & Edit Program Buffer Verify with Program Buffer Reload current Hex File Display Data Checksum Program selected Lock Bits & ISP fuse Parallel Port Selection LPT1, 2 & 3

Windows NT/2000/XP

To use the software with the above operating systems, an i/o port driver is required. There are many freeware

i/o port drivers are available on the web, the following port driver can be used with the Pgm89 programmer,

http://www.beyondlogic.org/porttalk/porttalk.htm

Study the web page and the readme file included in the port driver zip file for further information.

The programmer software uses the following i/o port addresses,

Lpt1 Port @ 378H

Lpt2 Port @ 278H

Lpt3 Port @ 3BCH

I/O Port @ 61H

I/O Port @ 42H & 43H

Note:

In order to insure safe insertion & removal of the u-controller from programmer ZIF socket make sure programmer power supply is turned on before starting the program and the red LED D1 must be turned off when the program is started. The u-controller should be placed or removed from the ZIF socket when the red LED D1 is off.

Also note that the software does not provide the erase command because this function is performed automatically during device programming. If you are required to erase the controller first use the clear buffer command in edit menu then program the controller, this will erase the controller memory.

Figure 4: Main screen of the program PGM89v3