p89c51rd2bn problems

[marcus]

Right, I am having real problems getting my program to work. I am using the P89C51RD2BN (not the -h version).

I have got my program to load, and I have variefied it. I then reprogram the status byte to PSEN (PSEN is diconnected from ground at this point, so that the hard activation of the bootloader is not in operation, but Vpp is still high for programming). It says it is successfully reprogrammed.

I then reset the chip with Vpp connected to Ground (which should activate the program since the status byte is set to 00 and my program starts at 0000H). All this does is activate the chip, but does not run my program.

Is there anything I am doing wrong which is very obvious? please help me!

[Andy Ayre]

If you pull EA/VPP down to ground then the device will execute from external code memory. Is that what you want?

[marcus]

nah, it is just using the internal flash memory.

[Andy Ayre]

Then you need to keep /EA pulled high.

[marcus]

ahhhh, thank you very much.