GND The cable should not be longer than 2m to avoid electrical reflections. Don't forget to: ATMEL AVR. connect a xtal and two capacitors (22pF) (See datasheed). use 5V power supply.
![Serial eeprom cross reference Serial eeprom cross reference](http://we.easyelectronics.ru/uploads/images/00/09/46/2014/09/14/b6b5a1.jpg)
connect a resistor from RESET to VCC. connect an capacitor (100nF) between Vcc and Ground as close to the chip as possible - avoid long lines. avoid differences in ground potential between your target hardware and the PC.
Find great deals on eBay for EPROM Programmer in Electrical Programmers. All serial numbers are recorded to prevent fraud and part swapping. The Microchip Technology Inc. 24LC256 is a 256Kb (32K x 8) Serial Electrically Erasable PROM (EEPROM), capable of 2.5V to 5.5V operation. It has been developed for advanced, low-power applications such as personal communications or data acquisition.
check what is connected to the portpins MOSI, MISO and SCK. These pins are used to program the chip. Your target board could response to these signals if something is connected to these pins. AT89S8252.
strap /EA (Pin 31 uC) to Vcc to operate from internal flash-memory. connect a xtal (4 - 24MHz) and two capacitors (22pF) (See datasheed). use 5V power supply. connect a capacitor and a resistor to RESET to get a power on reset. connect pullups to P0 if this port is used as output.
connect an capacitor (100nF) between Vcc and Ground as close to the chip as possible - avoid long lines. avoid differences in ground potential between your target hardware and the PC. check what is connected to the portpins P1.5, P1.6 and P1.7. These pins are used to program the chip. Your target board could response to these signals if something is connected to these pins.
If you have problems programming the device: - check 5V power supply - use the /TEST mode to check the programming interface - connect 10k resitors from MOSI, MISO and SCK to Vcc (sometimes nescessary for notebooks) - check if you use the right printer port - try programming in DOS mode if you use windows, sometimes a driver locks the port - check the xtal circuit - try /SLOW mode ATMEL AVR How to use the software: Download the program and extract the ZIP-file. Connect the micrcontroller to your PC and start the program with the following parameters: Usage: ISPAVR.EXE /LPTn /ERASE /LOCK /SLOW /READ /DATA /BO /TEST description:.
/LPTn use LPT1, LPT2 or LPT3 to select the printer port. /ERASE Erase code and data memory before writing. /LOCK Set lock bits after writing. /SLOW Use slower data transfer (in case of problems). /READ Read code/data memory. /DATA Program/Read the 2k data memory instead of code memory. /TEST Start hardware test mode.
/BO programs the brown-out fuses (if avalible). (4V and Reset 256ms +16k. ck) (see data sheed) Example 1: Write the file PROGRAM.BIN into the CODE memory and erase the chip first. The Programmer is connected to LPT1. ISPAVR.EXE /LPT1 /ERASE PROGRAM.BIN Example 2: Write the file DAT1.BIN into the DATA memory and do not erase the chip.
The Programmer is connected to LPT1. ISPAVR.EXE /LPT1 /DATA DAT1.BIN Example 3: Read the DATA memory and write to file CODE.BIN The Programmer is connected to LPT2. ISPAVR.EXE /LPT2 /READ CODE.BIN Example 4: Read the DATA memory and write to file DAT2.BIN The Programmer is connected to LPT2. ISPAVR.EXE /LPT2 /READ /DATA DAT2.BIN AT89S8252 How to use the software: Download the program and extract the ZIP-file. Connect the micrcontroller to your PC and start the program with the following parameters: Usage: ISPHB.EXE /LPTn /ERASE /LOCK /SLOW /READ /DATA /TEST description:.
/LPTn use LPT1, LPT2 or LPT3 to select the printer port. /ERASE Erase code and data memory before writing. /LOCK Set lock bits after writing. /SLOW Use slower data transfer (in case of problems). /READ Read code/data memory. /DATA Program/Read the 2k data memory instead of code memory.
/TEST Start hardware test mode Example 1: Write the file PROGRAM.BIN into the CODE memory and erase the chip first. The Programmer is connected to LPT1. ISPHB.EXE /LPT1 /ERASE PROGRAM.BIN Example 2: Write the file DAT1.BIN into the DATA memory and do not erase the chip. The Programmer is connected to LPT1.
![Eeprom Eeprom](http://www.willem-ua.com/_sh/00/26.jpg)
ISPHB.EXE /LPT1 /DATA DAT1.BIN Example 3: Read the DATA memory and write to file CODE.BIN The Programmer is connected to LPT2. ISPHB.EXE /LPT2 /READ CODE.BIN Example 4: Read the DATA memory and write to file DAT2.BIN The Programmer is connected to LPT2. ISPHB.EXE /LPT2 /READ /DATA DAT2.BIN.