ucfg1 & eprom

Hi Andrew,

// Header file for LPC764 MCU:
// #include "REG764.H"

// I.m using 87LPC76x contoller from
// Philips ( 8051 )

// no error, but not a value:
// xdata char P_UCFG1 _at_ 0xFD00;

// no error, but not a value:
// pdata const P_UCFG1 _at_ 0xFD00;

// syntax error near _at_:
// pdata const P_UCFG1=123 _at_ 0xFD00;

// syntax error:
// xdata char P_UCFG1=123 _at_ 0xFD00;

// absolute indentifier illegal:
// xdata char P_UCFG1 _at_ 0xFD00=2;

// syntax error:
// pdata const P_UCFG1 _at_ 0xFD00;

// invalid base adress:
// sfr P_UCFG1=0xFD00;

// In another compiler ( Tasking )
// this works:
// _rom char UCFG1 _at(0xFD00) = 0x7B
// Keil: missing ';' before 'char'

// In Keil assembler is works like this:
// org 0fd00h
// db 123

// the next is strange: compiler does
// not return an // error, but UCFG1
// is not listed in REG764.H. It has
// no effect.
// UCFG1=222;

// UCFG1 & UCFG2 is EPROM, nor RAM,
// not SFR of normal ROM ( code )

// Header file for LPC764 MCU:
// #include "REG764.H"

// no error, but not a value:
// xdata char P_UCFG1 _at_ 0xFD00;

// syntax error near _at_:
// pdata const P_UCFG1=123 _at_ 0xFD00;

// no error, but not a value:
// pdata const P_UCFG1 _at_ 0xFD00;

// syntax error:
// pdata const P_UCFG1 _at_ 0xFD00;

// In another compiler ( Tasking )
// this works:

// the next is strange: compiler does
// not return an // error, but UCFG1
// is not listed in REG764.H. It has
// no effect.
// UCFG1=222;

// UCFG1 & UCFG2 is EPROM, nor RAM,
// not SFR of normal ROM ( code )

Hi andrew, thanx again for fast your reply!

You are right that I cannot use the same code in different compilers. (unless ANSI C only) the reason I posted that code whas that I know how to solve the problem in Tasking C and also in Keil assembler, but not in Keil C. ( In Tasking:

 _rom char UCFG1 _at(0xFD00) = 0x7B 

If you know how to do it in Keil assembler, why not just do it in assembler!?
In this case, I don't think there is anything to gain in doing it in 'C'; in fact, assembler might even be better, as it allows you to write numbers in binary - which is easier to read when you're setting bit patterns (in 'C', you'd have to convert it to Hex).

Just create a little assembler file to set these two ROM "registers" - you don't even have to worry about C/Assembler interfacing, as there is nothing to "call" or be called; it just sets these 2 locations at build time.

When posting code to the forum, please enclose it within <pre> and </pre> tags (it gives you a monospaced font, and that lovely tuquoise tint!)

Are you complaining about my lovely turquoise tint? :-)

Jon