How to access register at 0X300005

Hans Wedemeyer · Joined: 15 Sep 2003 Posts: 226

PIC18F252
I need to set bit 0 of 0X300005 to 0

CONFIGURATION REGISTER 3 HIGH (CONFIG3H: BYTE ADDRESS 300005h)
Bit 0 is CCP2MX when set to 0 make Port B3 the output pin.

I seem to remember there is a way to do this with PCH

Data sheet implies it's the similar to writing eeprom... Either I made a mistake or it's lying to me...

Mark · Joined: 07 Sep 2003 Posts: 2838 Location: Atlanta, GA

It should be writing to program memory. I've never done it with CCS's function but it should do the trick. Try the write_program_memory() function.

Mark

Hans Wedemeyer · Joined: 15 Sep 2003 Posts: 226

OK that compiled, and I ran it... it did not work as expected...but else something strange happened...

ICD-2 now reports this error !

ICD0161: Verify failed (MemType = Program, Address = 0x0, Expected Val = 0xEFE9, Val Read = 0x0)
ICD0275: Programming failed.

This is strange. I've been using this prototype for about 3 weeks and programmed it about 20 time today alone.

Is this a coincidence or what !
Did the write_program_memory() clobber something !

I tired programming a second prototype and did not try to run the code.
It still programs !

It's a SMD chip so not so easy to swap out... Arrrgh!

Just in case anyone is interested here is the code that I used.

int i;

Read_Program_Memory(0X300005,&i,1); // one byte at a time
bit_clear( i, 0 ); // 0 then RB3 is PWM o/p
Write_Program_Memory(0X300005,&i,1);

Sad

Hans Wedemeyer · Joined: 15 Sep 2003 Posts: 226

I programmed the configuration bits only and here's the error messge.

ICD0161: Verify failed (MemType = Config, Address = 0x300001, Expected Val = 0x26, Val Read = 0x0)
ICD0275: Programming failed.

Looks like the chip got clobbered...

Tom-H-PIC · Joined: 08 Sep 2003 Posts: 105 Location: New Castle, DE

Hello Hans
I think what you are looking for is a FUSE setting.

I’m using the 18F452 and in checking the valid #Fuse keywords.
This is what I found.

Hans Wedemeyer · Joined: 15 Sep 2003 Posts: 226

I disconnected ICD-2 and cycled the power retsarted MPLAB and got this message when I tried to connect to the Debugger (ICD-2)

ICDWarn0020: Invalid target device id(expected-0x20, read=0x0)

The ICD-2 settings are correct. Connecting the the second protoype and MPLAB find the device no problem...

Whatever Wrtie_Program_memory() did it looks to me like it clobbered the chip ID location !

Anyone know a way to reset that !

I expect I'll have to change the chip.
Sad

Hans Wedemeyer · Joined: 15 Sep 2003 Posts: 226

Removed the SMD chip and soldered in a new one...
everything works....

Guest · Posted: Fri Dec 19, 2003 7:37 am

Tom-H-PIC · Joined: 08 Sep 2003 Posts: 105 Location: New Castle, DE

Yes I agree that this option would be able to be changed on the fly.
But there must be an issues with changing the configuration register at 0x30000x address.
Hans now has a chip that is junk.
I do know one think that is that if you don’t have the ICD-UXX setup for “Bulk erase on wirte “ under the advanced settings. That the ID address at 0x200000 etc. will not get set to 0xFFFF.
I’m think that maybe that the configuration registers will not get reset 100% if ICD not set to “Bulk erase on wirte “.
Hans if you want to save that other chip check your ICD setting under advanced.

Tom

Guest · Posted: Fri Dec 19, 2003 8:34 am