Flash Memory 256 Byte Programming Circuit

Circuit of AT89C51Manual Flash Memory Programmer

Component List that be Used.

Manual Instruction

         This AT89c51 flash manual programmer can be used in four mode, AT89c51 identity reading, Loading program, Program verification and program deleting.

• AT89c51 Identity Reading

Following steps are done to read the AT89c51 identity.

1. Switch off the power supply.

2. Put the AT89c51 in to ZIF socket.

3. Move the EA/VPP switch at 5 volt.

4. Move P2.6, P2.7, P3.6 and P3.7 switch at LOW.

5. Move the data switch at FFh (11111111b).

6. Switch on the power supply

7. Set the Address switch (switch A) with 30h (00110000b), the code will be seen at the data LED. (displaying LED  then be verified to AT89c51 datasheet).

8. Set the Address switch (switch A) with 31h (00110001b), the code will be seen at the data LED. (displaying LED  then be verified to AT89c51 datasheet).

9. Set the Address switch (switch A) with 32h (00110010b), the code will be seen at the data LED. (displaying LED  then be verified to AT89c51 datasheet).

10. Before put off the microcontroller, the power supply must be switched off.

•  Program Deleting

         Following steps are done to delete the program in AT89c51 flash memory.

1. Switch off the power supply.

2. Put the microcontroller in to ZIF socket.

3. Move the EA/VPP switch at 5 volt.

4. Move P2.6 switch at HIGH, P2.7, P3.6 and P3.7 switch at LOW.

5. Switch on the power supply.

6. Move EA/VPP switch at 12 volt.

7. Push the PROG button once.

8. Before put off the microcontroller, the power supply must be switched off.

•  Program Loading

            Following steps are done to load the program in to AT89c51 flash memory.

1. Prepare the program in LST file, then write down the instruction code for each address.

2. Switch off the power supply.

3. Put the microcontroller in to ZIF socket.

4. Move EA/VPP switch at 5 volt.

5. move P2.6 switch at LOW, P2.7, P3.6 and P3.7 at HIGH.

6. Switch on the power supply.

7. Set the address switch (switch A) with 00h (00000000b), (can be seen from the light of address LED).

8. Set the Data switch with appropriate hex code (hex code that will be loaded). And then move EA/VPP switch at 12 volt.

9. Push the PROG button once.

10. Remove EA/VPP switch at 5 volt.

11. Repeat step 7 to 10, with the data address add by 1.

12. Repeat all of steps until all of hex code is finished.

13. Before put off the microcontroller, the power supply must be switched off.

• Program Verifying 

   Following steps are done to verify the program that load in to AT89c51 flash memory.

1. Switch off the power supply.

2. Put the microcontroller in to ZIF socket.

3. Move EA/VPP switch at 5 volt.

4. Move P2.6, P2.7 switch at LOW, while P3.6 and P3.7 switch at HIGH.

5. Move the data switch at FFh (11111111b).

6. Switch on the power supply.

7. Set the address switch (switch A) with 00h (00000000b), (can be seen from the light of address LED).

8. Repeat the step 7, with the data address add by 1.

9. Repeat all steps above until the reading data is FFh for every next address.

10. Before put off the microcontroller, the power supply must be switched off.

11. If the hex code that is resulted same with the LST file, it can be concluded that the loading hex code is valid.