Im trying to get my 87C51 to read and write data to a peripheral (D71055). I'm using uVision3 and everything works fine with the debugger- I can see the data at the memory locations (0xF801) changing correctly as well as the other program functions. When I actually program the 87C51 chip and test it everything else works OK, but theres nothing on the D71055) I'm using volatile unsigned char xdata D71055_port_a_at_0xF800 volatile unsigned char xdata D71055_port_b_at_0xF801
ps. I've had success (data at 0xF801 reflects whats at 0xF800 correctly) with using a monitor program (paulmon) but I dont want to have that in my chip.
Thanks for feeding-back the conclusion!
Yes, timing is a classic cause of differences between "debug" and "real" versions...!