#org >64K

[Ian McCrum]

Hi, I am currently working with a 18C801, this has no internal ROM and allows up to 2MBytes of external memory. Curent wirewrap board has 128k of flash and 128k of RAM.

I want to download executable code into the RAM, which starts at 0x20000 and then provide the user with a 'G' command to start executing it
(just the liike the good old days of mikbug and beyond...)

I have the bootloader/monitor code written and mainly working, just about ('G' is tricky...)
I need to generate code that starts at 128k and not 0x0000

I belive the statements below should do this, but they don't ( I dissassembled the code)

#build (RESET=0x20000)
#org 0x20000,0x2FFFF default

// syntax above is approximate, I am away from my own Pc at present)

The #org's produce assembler with the address clipped to the bottom 64k.
How do I set the #ORG to a value >64k ?
TIA
Ian
_________________
Ian McCrum, email address held at
www.eej.ulst.ac.uk/~ian

[jaremek16]

At first address of #build must be out of range #ORG, try:

[Ian McCrum]

Thanks Jarek, I have also emailed you, your advice above works great, provided the addresses are less than 64k, here is code that breaks

___

// Bug/Feature in #ORG ... it is restricted to 64K
// Compiled with Version 3.120 (PCH)
// But the 18C801 can have 2 MByte of program space
// Ian McCrum , University of Ulster

#include <18C801.h>
#use delay(clock=20000000)
#use rs232(baud=2400, xmit=PIN_C6,rcv=PIN_C7)

// If you swop the two lines below by adding trailing ZEROs
// you get an error : Internal Error -Contact CCS => Code 65.0.11
//
#build (RESET=0x2000)
#org 0x2002,0x20FF DEFAULT
//#build (RESET=0x20000)
//#org 0x20020,0x20FF0 DEFAULT
void main() {
while(TRUE){
putc('+');
}//---- end while ----
}//---- end main ----

__
the working code assembles to 30 words of program and looks great, the internal error is a bit of a nusiance. Must read up to see if I can post process the intel hex file to relocate code... <sigh>
_________________
Ian McCrum, email address held at
www.eej.ulst.ac.uk/~ian

[jaremek16]

Hi Ian
I had also this problem but I solved it by reserve rest of lower memory.
(sorry for my english if you didn't understand me, I still learn)
Try this:

[Ian McCrum]

Many many thanks for your reply, Jarek.

I have pasted your code into my compiler and I still get a CCS internal error 65:0:11, even after altering the memory size in the device editor.

I use PCH version 3.120 and note in the CCS website that it has bugs that were fixed...

// Note: http://www.ccsinfo.com/versions.shtml ... list of bugs
//
// 3.140 Some internal limits increased to permit very large programs
// 3.165 Some bugs with programs > 128K are now fixed
// 3.177 A problem with #org's over 0x20000 is fixed <<<<<
// 3.179 Better support for parts with external memory has been added
// 3.188 New separate bootloader examples have been added
// 3.189 Some #org issues have been addressed <<<<<<<

I have emailed CCS, maybe they will help a poor University that has bought a compiler that was sold "not fit for the purpose it was bought for"
8-(
<sigh>

The quickest fix is for me to upgrade.

Thanks again for your time.
Kindest Regards
Ian

__
_________________
Ian McCrum, email address held at
www.eej.ulst.ac.uk/~ian