18 years ago
I'm really losing my mind now, been fighting with this for 8 days
now, I give up. I hope you can tell me what's wrong in my setup. :(
I self made a PIC18F8720 development board, and it seems to work,
because I can program the chip with no problems.
I'm using 100 nF SMD capacitors near every Vdd (including AVdd),
and an integrated clock oscillator. It's a 24 MHz CMOS part by
I wrote a simple test program which is supposed to set all ports
to output (via the TRISx registers), and then put all of them to
the "HIGH" logic level (via the PORTx registers).
This is my code, as shown by IC-Prog:
0000: D00F 0000 0000 0000 0000 0000 0000 0000
0008: 0000 0000 0000 0000 0000 0000 0000 0000
0010: 0000 0E00 6E92 6E93 6E94 6E95 6E96 6E97
0018: 6E98 6E99 6E9A 0000 0000 0000 0000 0000
0020: 0EFF 6E80 6E81 6E82 6E83 6E84 6E85 6E86
0028: 6E87 6E88 0000 0000 0000 0000 0000 0000
0030: D7DE 0000 0000 0000 0000 0000 0000 0000
And this is the configuration:
Config1 = 2500
Config2 = 000F
Config3 = 0080
Config4 = 0081
Config5 = C0FF
Config6 = E0FF
Config7 = 40FF
ID Value = 0123456789ABCDEF
Is there anything wrong in my machine code (for this quick test
I don't want to nor I think I need to install MP-Lab.. I tried
it and hated it, I will write my own source level debugger and
assembler and release it to the PD after I'm finished).
Is the reset vector ok? It's supposed to be a BRA to 0010, where
it will meet a NOP (no reason in particular) and then the value
00 will be moved to W, which in turn will be moved to all the
TRISx registers. Then W will be loaded with FF, which will be
copied to all the PORTx registers. Finally (through some NOPs,
again, just to leave some space for inserting other code for
experiments) there's supposed to be a final BRA back to 0010.
Addresses don't represent bytes, but instruction words.
I know it's tedious to go through machine code.. but if you're
kind enough, and if the code or the configuration is wrong, please,
can you point me to the errors?
Or, in alternative, could some kind soul post a small .HEX file
with a demo program that just turns some port pins ON and some
others OFF, just to see if my problem lies in my hardware or in
I hope to get your valuable help.. I really don't know what to