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picerno
Guest
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| locating in eeprom |
 Posted: Tue Oct 10, 2006 5:22 am |
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Hi, can I "#locate" an array in eeprom?
I want to access an eeprom area writing or reading an array:
array[0] = 10;
temp = array[0];
Is it possible?
thanks! |
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Tue Oct 10, 2006 8:11 am |
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| Data EEPROM of the chip? or external eeprom? |
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picerno
Guest
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| locating in eeprom |
| Posted: Tue Oct 10, 2006 12:10 pm |
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| I want to locate in internal eeprom, but is it possible in external also? |
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Ttelmah
Guest
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| Posted: Tue Oct 10, 2006 2:38 pm |
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Typemod.
This allows you to have variables declared using external storage (EEPROM etc.), and use them in your code. There i a fairly large overhead associated with this, and some temporary storage used. Gnerally it is only therefore 'worthwhile' for large external memories,rather than with th internal EEPROM.
Best Wishes |
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treitmey
Joined: 23 Jan 2004
Posts: 1094
Location: Appleton,WI USA
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| Posted: Tue Oct 10, 2006 2:48 pm |
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V3.249 16F877A@20MHz
This is for internal data_eeprom
External can be used if you have the chip(24LC64). It is done differently
| Code: | #include <16F877A.h>
#device *=16
#fuses hs,nowdt,noprotect,nolvp,put
#use delay(clock=20000000)
#use rs232(baud=19200,xmit=PIN_E2,invert,stream=debug,disable_ints)
#case
#zero_ram
//The below ROM is programed as the chip is programed
#define _array_1 0x2100 //note how 0x2100 is data_eprom location 0
#rom _array_1={0xBA,0xBB,0xBC,0xBD,0xBE,0xBF}
//--- Prototypes ---//
void DataEE_Write(int32 address, int8 * data, int8 size);
void DataEE_Read (int32 address, int8 * data, int8 size);
//--- Data EEPROM ---//
addressmod <,DataEE_Read,DataEE_Write,0x00,0xFF> DataEE;
//--- main ---//
main(){
int8 DataEE array[10];
fprintf(DEBUG,"Start\n\r");
fprintf(DEBUG,"0x%X\n\r",array[0]);
fprintf(DEBUG,"0x%X\n\r",array[1]);
fprintf(DEBUG,"0x%X\n\r",array[2]);
fprintf(DEBUG,"Done\n\r");
while(1);
}
// Below should be read-before-write
// First Read data. Then only write if the information is different
// Takes longer but cuts down on writes that can wear out the eeprom
////--- DataEE_Write ---//
//void DataEE_Write(int32 address, int8 * data, int8 size){
// //shell function to test if call is made. Doesn't do anything
// int i;
// fprintf(DEBUG,"W-A=%lu, S=%u\n\r",address,size);
// for(;size;size--,data++,address++){
// write_eeprom(address,*data);
// }
//}
//--- DataEE_Read ---//
void DataEE_Read(int32 address, int8 * data, int8 size){
for(;size;size--,data++,address++){
*data=read_eeprom(address);
}
}
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This will add a bunch to the RAM usage because the compiler is taking care of the addresses for you. I find it better to just #ROM and read with a straight read_eeprom(address); |
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picerno
Guest
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| locating in eeprom |
| Posted: Wed Oct 11, 2006 2:04 am |
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| it is interesting, but I don't find documentation about "addressmode". What'is this? |
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Ttelmah
Guest
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| Posted: Wed Oct 11, 2006 2:13 am |
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Typemod, and addressmod, are different names for the same thing. The 'older' name was typemod, and in V4, it is to be called 'addressmod'. V3.249, supports both. If you go to the CCS main page, and type 'typemod' into the search, the top entry, gives an example page showing how it is used, and what it can do.
Best Wishes |
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picerno
Guest
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| Posted: Wed Oct 11, 2006 2:28 am |
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Wonderful, I will try it with a 3D array. It will work?
thanks, thanks |
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