Ho all, i've a little app, i'm using a DS89C430, an external flash 29F040 70nsec, an external SRAM 70nsec.

My issue is that, the little firmware app i've written don't work "only for this chip": the test code sample make blink a led and put out some chars from the serial 0 port.

Try to explain:
If i put on the socket the DS89C430, the led blink, (code fetched correctly) but everytime the code use a *p++ or an array, it fail. If i put char out fron the serial using SBUF0, it works, chars come to the PC terminal, i can see them right. But if i go with printf overloaded, or just using *p++, this fail.

If i put on the socket a DS87C520, similar but with internal eprom, everything works fine. Anyway, from datasheets, both chip are similar, and have as default a std 8051 behaviour.

If i put on the socket again the DS89C430, the led blink, (code fetched correctly) but everytime the code use a *p++ or an array, it fail. I've read the pointer value trough SBUF0, it is 0140h, pointing correctly the xdata ram position. But it get no values out from the sram.

If i work at 25 mhz or at 4mhz, the issue remain the same.
At 25Mhz, PSEN HIGH and LOW parts are, seen with mi HP54201 digital oscilloscope, 80 nsec, so over 70nsec access time of flash and ram.

I really don't know what other test to do, hope in some help.

Infinite thanks, Angelo