Atmel AT89S8252 In-Circuit Programmer
- Download the program (runs under Win95 & 98),
and unzip into a permanent directory. Place a shortcut on the desktop to
- See the circuit diagram for detailed programmer
- The programmer has a 40-pin ZIF socket for programming parts out of circuit. To
operate in this mode, use a parallel cable to connect LPT1 on the PC to the DB25 on the
programmer; the LED on the programmer should glow dimly. Attach the external power
supply to the programmer; the green LED now should be bright. Pin 1 of the Atmel
AT89S8252 should be positioned at the top of the ZIF socket (nearer to the LED).
- To program a part in-circuit, the design must have included a 6x2 programming header
with the appropriate configuration. See the following two circuits for examples of
how to wire this header: (circuit #1, circuit#2). When ready to program:
- attach the programmer to LPT1
- turn circuit power off
- attach the special DB9-to-6x2-AMP-header cable between the programmer and the
- turn on circuit power
- Click on the arrow button to load an Intel-hex or binary
file. The A51.exe 8051-assembler generates an Intel-hex output (.obj). The
in-circuit software will generate binary (.bin) files both upon loading an Intel-hex file
and when saving the contents of an AT89S8252 flash. The Reload
button reloads the displayed file. Click on Contents to
view the data contained in the file. The number of bytes in the file will be
displayed above the filename.
- Click on Program to load and verify the code contained in
the specified file. Make sure the part is loaded in the ZIF socket or the
programming header is attached, and make sure power is applied (external supply if ZIF
socket used, and circuit power if programming header is used).
- Click on Erase to empty the contents of the
microcontroller. Click on Read to read out the
microcontroller flash. Once flash contents have been loaded into the PC memory, a
"LOADED" flag will appear. At this point, click on Contents
to view the flash data or Save to store the flash data as a
binary file. The number of bytes in the flash will appear above the Read button.
- The Compare button checks if the data in the displayed file
matches the data read from the flash. Data in the flash located after the last
address in the file has no impact on a comparison.
NOTE: when reading the flash, the programming software stops when it sees a
string of 50 bytes in a row with the same value. In the event that a program
contains 50 consecutive equal values, a read of the flash WILL TERMINATE PREMATURELY.
This would happen, for example, in programs with large address separations between
code chunks. Programming the flash is not affected by the 50-byte rule; only a read
operation may be impacted.