Hi,

well I tried the down load tool isp_hb.exe from www.microcontroller.de. I build a new cable. Testing the cable looked good. All required signals could be measured at the Pins of the 8252 (Rest, MOSI, SCK, MISO). The tool offers a test mode. During the test mode the status of each signal can be changed and the logical status could be measured (scope) directly at the pins of the 8252.

Now I tried to down load the flash1.asm binary code. The tool send the first byte (74H at Adress 0000h) to the target and immediatly tried to read back the first byte. The value of the read back byte is ffH. The tool now terminated with an error. I know that I previously programmed the flash with a small programm writing a 00h to port1 pins and then hang in an endless loop. My LED connected to the P1.3 is ON. The Pin p1.3 is LOW as all other Pins of Port1 after reset or power on.

Well to me it looks like that the new code is not programmed to the flash memory or the flash memeroy can not be read.

At the moment I donot know what the problem is.

As I read in the manual of the 8052 the lock bits can only be unprogrammed with the chip erase operation during programming mode (RESET = 1; serial). The tool I used offers the ERASE command but this also did not lead to any success.


PS.: Thorsten, I am from Germany!