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karthickiw
Joined: 09 Aug 2007
Posts: 82
Location: TN, India
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| Problem with External eeprom... |
 Posted: Wed Jun 24, 2009 9:21 am |
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Dear CCS Friends,
I write a program for write and read the string in external eeprom. After finished my code, I write the three string data in specified locations. After that I read one by one location, I received wrong data for (17*13) location and other location data are correct.
| Code: |
#include "2464.c"
void write_ext(long int add,char data[])
{
long int loc=0;
for (loc = 0; loc <= strlen(data); loc++)
{
if ( loc < strlen(data)) write_ext_eeprom((loc+add), data[loc]);
else write_ext_eeprom((loc+add), '\0');
}
}
void read_ext(long int add)
{
long int loc=0;
char data[];
for (loc = 0; loc < 13; loc++)
{
if (read_ext_eeprom(loc+add)=='\0')
{
data[loc]=read_ext_eeprom(loc+add);
break;
}
else
{
data[loc]=read_ext_eeprom(loc+add);
}
}
printf("%S\n\r",data);
}
void main()
{
char name[15];
long int j=0;
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(SPI_SS_DISABLED);
setup_wdt(WDT_OFF);
setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_timer_3(T3_DISABLED|T3_DIV_BY_1);
//Setup_Oscillator parameter not selected from Intr Oscillotar Config tab
printf("Start...\n\r");
init_ext_eeprom();
delay_ms(20);
.
.
.
.
.
.
sprintf(name,"%s","Programmer");
write_ext(15*13,name);
delay_ms(20);
sprintf(name,"%s","Karthic");
write_ext(16*13,name);
delay_ms(20);
sprintf(name,"%s","Welcome");
write_ext(17*13,name);
delay_ms(20);
.
.
.
.
while(true)
{
read_ext((15*13));
delay_ms(1000);
read_ext((16*13));
delay_ms(1000);
read_ext((17*13));
delay_ms(1000);
}
}
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For my program I received below answer in hyper terminal.
| Quote: | Start….
Programmer
Karthic
Karthic
|
I using PIC18LF452 controller and 24C64 EEPROM.
Please check my code and give idea for my problem... 
two question regarding 24C64 IC
1) How many byte is store in 24C64 eeprom?. i see the datasheet, but have little confusion.
2) i want to store the 4MB of data, for that what type of memory is used?. Please give any suggestion . |
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FvM
Joined: 27 Aug 2008
Posts: 2337
Location: Germany
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| Posted: Wed Jun 24, 2009 11:21 am |
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How much storage do you expect to be assigned by CCS C with this variable definition?
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mkuang
Joined: 14 Dec 2007
Posts: 257
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| Re: Problem with External eeprom... |
| Posted: Wed Jun 24, 2009 11:24 am |
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The part has 64kbit or 8 kbytes of storage. You would likely address it using a number from zero to 7999. Your function declaration here is not correct:
| Code: |
void write_ext(long int add,char data[])
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If you want a function to accept an array as an input you have to declare a pointer to the first element of the array like:
| Code: |
void write_ext(long int add,char* data)
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Jun 24, 2009 12:26 pm |
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| Quote: | | You would likely address it using a number from zero to 7999 |
The size numbers in the eeprom data sheet are binary, not decimal.
It has 8192 bytes. The address range is from 0 to 8191.
| Quote: | | Your function declaration here is not correct: |
In fact, it works fine. The test program shown below displays the
following output:
| Code: | #include <16F877.H>
#fuses XT, NOWDT, NOPROTECT, BROWNOUT, PUT, NOLVP
#use delay(clock=4000000)
#use rs232(baud=9600, xmit=PIN_C6, rcv=PIN_C7, ERRORS)
void write_ext(long int add, char data[])
{
printf("%s", data);
}
//==================================
void main()
{
int8 buffer[32];
strcpy(buffer, "Hello World");
write_ext(0, buffer);
while(1);
} |
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karthickiw
Joined: 09 Aug 2007
Posts: 82
Location: TN, India
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| Full actual Program |
| Posted: Wed Jun 24, 2009 12:39 pm |
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Dear Friends,
Thank you for your idea, but still I have a problem during read the 17*13 location...
| Code: |
#include <18F452.h>
#device adc=8
#include <string.h>
#FUSES NOWDT //No Watch Dog Timer
#FUSES WDT128 //Watch Dog Timer uses 1:128 Postscale
#FUSES XT //High speed Osc (> 4mhz)
#FUSES PROTECT //Code protected from reads
#FUSES NOOSCSEN //Oscillator switching is disabled, main oscillator is source
#FUSES BROWNOUT //Reset when brownout detected
#FUSES BORV20 //Brownout reset at 2.0V
#FUSES PUT //Power Up Timer
#FUSES STVREN //Stack full/underflow will cause reset
#FUSES NODEBUG //No Debug mode for ICD
#FUSES NOLVP //Low Voltage Programming on B3(PIC16) or B5(PIC18)
#FUSES WRT //Program Memory Write Protected
#FUSES WRTD //Data EEPROM write protected
#FUSES WRTB //Boot block write protected
#FUSES WRTC //configuration registers write protected
#FUSES CPD //Data EEPROM Code Protected
#FUSES CPB //Boot Block Code Protected
#FUSES EBTR //Memory protected from table reads
#FUSES EBTRB //Boot block protected from table reads
#use delay(clock=4000000)
#use rs232(baud=9600,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8)
#include "2464.c"
void write_ext(long int add,char* data)
{
long int loc=0;
for (loc = 0; loc <= strlen(data); loc++)
{
if ( loc < strlen(data)) write_ext_eeprom((loc+add), data[loc]);
else write_ext_eeprom((loc+add), '\0');
}
}
void read_ext(long int add)
{
long int loc=0;
char data[];
for (loc = 0; loc < 13; loc++)
{
if (read_ext_eeprom(loc+add)=='\0')
{
data[loc]=read_ext_eeprom(loc+add);
break;
}
else
{
data[loc]=read_ext_eeprom(loc+add);
}
}
printf("%S\n\r",data);
}
void main()
{
char name[15];
long int j=0;
setup_adc_ports(NO_ANALOGS);
setup_adc(ADC_OFF);
setup_psp(PSP_DISABLED);
setup_spi(SPI_SS_DISABLED);
setup_wdt(WDT_OFF);
setup_timer_0(RTCC_INTERNAL);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
setup_timer_3(T3_DISABLED|T3_DIV_BY_1);
//Setup_Oscillator parameter not selected from Intr Oscillotar Config tab
printf("Start...");
init_ext_eeprom();
delay_ms(20);
////////////////////////12 character size without null///////////////////////
sprintf(name,"%s","Erode");
write_ext(0,name);
delay_ms(100);
sprintf(name,"%s","Savitha");
write_ext(1*13,name);
delay_ms(100);
sprintf(name,"%s","PS Park");
write_ext(2*13,name);
delay_ms(100);
sprintf(name,"%s","GH");
write_ext(3*13,name);
delay_ms(100);
sprintf(name,"%s","Sathiyam Hos");
write_ext(4*13,name);
delay_ms(100);
sprintf(name,"%s","Collector of");
write_ext(5*13,name);
delay_ms(100);
sprintf(name,"%s","Kumalan kutt");
write_ext(6*13,name);
delay_ms(100);
sprintf(name,"%s","palayapalaya");
write_ext(7*13,name);
delay_ms(100);
sprintf(name,"%s","Veer Palayam");
write_ext(8*13,name);
delay_ms(100);
sprintf(name,"%s","Sengotampala");
write_ext(9*13,name);
delay_ms(100);
sprintf(name,"%s","Thindal");
write_ext(10*13,name);
delay_ms(100);
sprintf(name,"%s","Thindal medu");
write_ext(11*13,name);
delay_ms(100);
sprintf(name,"%s","Pavalathan p");
write_ext(12*13,name);
delay_ms(100);
sprintf(name,"%s","Veppanpalaya");
write_ext(13*13,name);
delay_ms(100);
sprintf(name,"%s","Mettukadai");
write_ext(14*13,name);
delay_ms(100);
sprintf(name,"%s","Vannankattu");
write_ext(15*13,name);
delay_ms(100);
sprintf(name,"%s","Moolakkarai");
write_ext(16*13,name);
delay_ms(100);
sprintf(name,"%s","Sathiramput");
write_ext(17*13,name);
delay_ms(100);
sprintf(name,"%s","Koorapalayam");
write_ext(18*13,name);
delay_ms(100);
sprintf(name,"%s","Vaaikkalmedu");
write_ext(19*13,name);
delay_ms(100);
sprintf(name,"%s","Maharaja col");
write_ext(20*13,name);
delay_ms(100);
sprintf(name,"%s","Kanthampalay");
write_ext(21*13,name);
delay_ms(100);
sprintf(name,"%s","Police stati");
write_ext(22*13,name);
delay_ms(100);
sprintf(name,"%s","Perundurai");
write_ext(23*13,name);
delay_ms(100);
while(True)
{
read_ext((j*13));
output_high(pin_a0);
delay_ms(500);
output_low(pin_a0);
delay_ms(500);
j++;
if (j==24) j=0;
}// while
}
|
output from hyper terminal
| Quote: | Start...Erode
Savitha
PS Park
GH
Sathiyam Hos
Collector of
Kumalan kutt
palayapalaya
Veer Palayam
Sengotampala
Thindal
Thindal medu
Pavalathan p
Veppanpalaya
Mettukadai
Vannankattu
Moolakkarai
Moolakkarai --->This is problem string (actual here present Sathiramput)
Koorapalayam
Vaaikkalmedu
Maharaja col
Kanthampalay
Police stati
Perundurai |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Jun 24, 2009 12:41 pm |
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| Quote: |
For my program I received below answer in hyper terminal.
Start….
Programmer
Karthic
Karthic
|
So apparently your complaint is that it's repeating "Karthic" instead
of displaying "Welcome" ? Post some more of the output. Does it
only display "Karthic" after the initial lines ?
Post your #fuses statement. |
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mkuang
Joined: 14 Dec 2007
Posts: 257
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| Posted: Wed Jun 24, 2009 12:59 pm |
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That and he is getting the same string at 17*13 as 16*13 for some reason. Going back this looks a bit fishy:
| Code: |
void read_ext(long int add)
{
long int loc=0;
char data[];
}
|
I don't know whether you can allocated memory for an array without telling the compiler how big the array is. I would try something like:
| Code: |
char data[23]; //is that how many names you have there?
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Jun 24, 2009 1:03 pm |
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| Quote: | Going back this looks a bit fishy:
void read_ext(long int add)
{
long int loc=0;
char data[];
data[loc]=read_ext_eeprom(loc+add);
|
I agree. He's writing to an array which doesn't have any RAM allocated
for it, because the size was not specified. He is likely to be over-writing
other RAM locations. |
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FvM
Joined: 27 Aug 2008
Posts: 2337
Location: Germany
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| Posted: Wed Jun 24, 2009 4:45 pm |
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| Yes, it's been said, but he doesn't hear. |
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karthickiw
Joined: 09 Aug 2007
Posts: 82
Location: TN, India
|
| Problem not solve... |
| Posted: Wed Jun 24, 2009 8:49 pm |
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Thank you PCM,FvM and mkuang. now i specified the array size in read_ex function, then also my problem is not solved..
| Code: | void read_ext(long int add)
{
long int loc=0;
char data[15];
for (loc = 0; loc < 13; loc++)
{
if (read_ext_eeprom(loc+add)=='\0')
{
data[loc]=read_ext_eeprom(loc+add);
break;
}
else
{
data[loc]=read_ext_eeprom(loc+add);
}
}
printf("%S\n\r",data);
} |
my output is
| Code: | Start...Erode
Savitha
PS Park
GH
Sathiyam Hos
Collector of
Kumalan kutt
palayapalaya
Veer Palayam
Sengotampala
Thindal
Thindal medu
Pavalathan p
Veppanpalaya
Mettukadai
Vannankattu
Moolakkarai
Moolakkarai --->This is probelm string( actual here present Sathiramput)
Koorapalayam
Vaaikkalmedu
Maharaja col
Kanthampalay
Police stati
Perundurai |
[quote="PCM programmer"] | Quote: | Going back this looks a bit fishy:
void read_ext(long int add)
{
long int loc=0;
char data[];
data[loc]=read_ext_eeprom(loc+add);
|
| Quote: |
I agree. He's writing to an array which doesn't have any RAM allocated
for it, because the size was not specified. He is likely to be over-writing
other RAM locations. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Jun 24, 2009 9:55 pm |
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Are you running this test in actual hardware or are you running it in
Proteus or ISIS or something like that ? |
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karthickiw
Joined: 09 Aug 2007
Posts: 82
Location: TN, India
|
| response |
| Posted: Thu Jun 25, 2009 5:50 am |
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| PCM programmer wrote: | Are you running this test in actual hardware or are you running it in
Proteus or ISIS or something like that ? |
im running program in hardware and when i add printf statement like below code means, im get correct output....
| Code: |
.
.
.
.
.
sprintf(name,"%s","Mettukadai");
write_ext(14*13,name);
delay_ms(100);
sprintf(name,"%s","Vannankattu");
write_ext(15*13,name);
delay_ms(100);
sprintf(name,"%s","Moolakkarai");
write_ext(16*13,name);
delay_ms(100);
printf("%s",name); ---> when add this line, my result is correct.when remove means i get wrong result
sprintf(name,"%s","Sathiramput");
write_ext(17*13,name);
.
.
.
.
. |
| Code: | Start...Erode
Savitha
PS Park
GH
Sathiyam Hos
Collector of
Kumalan kutt
palayapalaya
Veer Palayam
Sengotampala
Thindal
Thindal medu
Pavalathan p
Veppanpalaya
Mettukadai
Vannankattu
Moolakkarai
Sathiramput --->this is correct result, when remove the printf i get Moolakkarai for this sathiramput
Koorapalayam
Vaaikkalmedu
Maharaja col
Kanthampalay
Police stati
Perundurai |
please give correct solution for this probelm.. |
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FvM
Joined: 27 Aug 2008
Posts: 2337
Location: Germany
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| Posted: Thu Jun 25, 2009 7:06 am |
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| The text should be printed twice now. Is the second copy (from read_ext)also correct? |
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karthickiw
Joined: 09 Aug 2007
Posts: 82
Location: TN, India
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| thank you |
| Posted: Thu Jun 25, 2009 8:23 am |
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| FvM wrote: | | The text should be printed twice now. Is the second copy (from read_ext)also correct? |
Text printed twice time. Second copy also correct. |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Thu Jun 25, 2009 1:56 pm |
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You said "Thank You". Does that mean the problem is solved ?
Is it working OK ?
If not, then post your compiler version. |
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