value at fixed memory address

[redkofka]

Posted on July 03, 2012 at 08:32

hi i want to place value - ''address of station'' at fixed memory address

without specifed address its look like &sharpdefine mcu_address 0x03 i found - it may looks like &sharpdefine mcu_address         (*((volatile unsigned long *) 0x20000000)) mcu_address = 0x03;    //here i have syntax error i am using coocox ide... thanks for all ideas ... #value-address

[Tesla DeLorean]

Posted on July 03, 2012 at 12:39

Both Keil 4.53 and GCC 4.7.1 are tolerant of that, perhaps a more complete exemplar that demonstrates the issue would help. Is it the compiler or the IDE reporting this error, which version of GCC?

The typical method is unsigned long *foo = (unsigned long *)0x20000000; *foo = 12345; foo[1] = 67890;

[Andrew Neil]

Posted on July 03, 2012 at 23:47

''here i have syntax error''

You need to show the full text of the error. And, as clive1 says, you also need to show a complete example.

[redkofka]

Posted on July 04, 2012 at 07:38

ok -

so i used this in my code and it works great : #define rts_1        GPIOA->ODR |=  (1 << 12);                //rs485 #define rts_0        GPIOA->ODR &= ~(1 << 12);            //rs485 #define adresa 0x03               then i have something like rx_packet 24byte - adress of mcu is on rx_packet[2] in code i check if address is valid if  (adresa ==rx_packet[2] ){Decode_Packet(p);} /***************************************/ when i used this definition #define mcu_address         (*((volatile unsigned long *) 0x20000000)) mcu_address = 0x03;    //here i have syntax error -it show ''?'' in coocox and in compile log i have        [cc] C:\CooCox\CoIDE\workspace\DMA\main.c:93: error: expected identifier or '(' before 'volatile'        [cc] C:\CooCox\CoIDE\workspace\DMA\main.c:93: error: expected ')' before numeric constant so i tried used clive's example unsigned long *foo = (unsigned long *)0x20000000; *foo = 12345;    // error: conflicting types for 'foo' foo[1] = 67890; //  error: conflicting types for 'foo' and  error: invalid initializer i use gcc arm-none-eabi-gcc-4.4.1 all in all i only want to have const or variable of device address on my memory adress where i want .... thanks for yours posts guys ...