Hello small question, for my program I use eight large static arrays like,
static unsigned long SP1[64]
and these arrays contains constant values that I need for some calualation in my program this values are never changed. The program code are located in program flash memory. If I remember correctly during the runtime the variable are located (or. copy) in the internal RAM or SRAM (if I use xhuge command for declaration, I found this with the keyword: memory model). Now my question, is it possible to get this values out of the external flash memory area during the runtime of the program?.
This answer seems too simple:
unsigned long v; : v = SP1[0]; // read value of SP1[0]
Is this really your question?
Unfortunately not, the read out of a value from the array is simple (you descript it above). But my question is not so simple maybe I explain a little bit more.
My memory mapping contains the follwing information
HCONST (0X4200-0XEFFF, 0X10000-0X7F1FE) IDATA (0XFA00-0XFDFF) HDATA (0X100000-0X13FFEF) XDATA (0X100000-0X13FFEF)
with a declaration
I think the array will located in internal RAM
In the meantime I read some user guides and hints and I make my declaration thusly like
static unsigned long const xhuge SP1[64]
in the listing file contains the following infos
SP1 . . . . . static XCONST array 100H 256 MODULE INFORMATION: INITIALIZED UNINITIALIZED CODE SIZE = 4276 -------- NEAR-CONST SIZE = -------- -------- FAR-CONST SIZE = -------- -------- HUGE-CONST SIZE = 20 -------- XHUGE-CONST SIZE = 2304 -------- NEAR-DATA SIZE = -------- -------- FAR-DATA SIZE = -------- -------- XHUGE-DATA SIZE = 384 -------- IDATA-DATA SIZE = -------- -------- SDATA-DATA SIZE = -------- -------- BDATA-DATA SIZE = -------- -------- HUGE-DATA SIZE = -------- -------- BIT SIZE = -------- -------- INIT'L SIZE = 30 -------- END OF MODULE INFORMATION.
My Program Flash (512kByte) as the physical adress 00 0000H - 08 0000H (internal RAM and SFR's 00 F0000h 01 0000H) Now my question once again, can everbody say to me where the array is physical stored in IRAM or in the external Flash?
The best way to verify the physical address is to take a look to the linker map file (*.M66 for 166 projects).
Take a look to: http://www.keil.com/support/man/docs/c166/c166_ap_sgc.htm
What you may have missed is the definition for the XCONST memory class that allows you to locate variables that are define with const xhuge.
See also: http://www.keil.com/support/man/docs/l166/l166_pm_example3.htm
OK, first thanks for your answer thats helps
second the position of XCONST is
XCONST (0X4200-0XEFFF, 0X10000-0X7F1FE)
Could you explain to me what are the differenc between the first and the second settings by XCONST
XCONST (first settings, second settings)
In special, which memory area (first,second settings) will use if I make a declaration like follow