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Atma
Joined: 08 Aug 2005
Posts: 22
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| Programming a PIC |
 Posted: Wed Nov 09, 2005 5:33 am |
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Hi there
I am trying to program a PIC with another PIC. I managed to read the target ID of the device and i manged to erase the device. Now i am trying to program the device. I tried sending one byte(hard coded - defined as a) to write to the memory and then used a normal programmer (ICD2) to read back the target PIC and see if the byte was written in memory but it wasnt.when i checked with the oscilloscope, i could see the bits coming out(sent) on the data pin when the clock pin cycled 16 times but couldnt read it. I have pasted my code below. Can anyone tell me what I am doing wrong?
| Code: |
int8 a = 0xCB;
int PIC_HEX_ProgMem_LastLoadedAddress;
#define P_MCLR PIN_B0 //Pin MCLR
#define P_DATA PIN_B2 //pin RB7
#define P_CLOCK PIN_B1 //pin RB6
#include <16F873.h>
#use delay(clock=20000000)
#fuses XT,NOWDT,BROWNOUT, PUT, NOLVP
#use rs232(baud=115200,parity=N,xmit=PIN_C6,rcv=PIN_C7,bits=8)
typedef int16 WORD;
typedef short BOOL;
//typedef int16 FILE;
#define PIC_CMD_LOADCONFIG 0x00
#define PIC_CMD_LOADPROGRAM 0x02
#define PIC_CMD_READPROGRAM 0x04
#define PIC_CMD_BEGINERASEPROGRAM 0x08
#define PIC_CMD_INCADDRESS 0x06
#define PIC_CMD_LOADDATA 0x03
#define PIC_CMD_BULKERASE1 0x01
#define PIC_CMD_BULKERASE2 0x07
#define PIC_CMD_ENDPROGRAM 0x0E
#define PIC_CMD_BEGINPROGRAM 0x18
#define PIC_HEX_ID_BUFFER_SIZE 4 /* max size of ID memory */
#define PIC_HEX_NR_CONFIG_WORDS 2
#define PIC_HEX_PROG_BUF_SIZE 8192 /* max size of program memory */
#define buffersize 64
#define lConfMemBase 0x2000
#define lConfWordAdr 0x2007
#define wCfgmask_bandgap 0x0000
#define wCfgmask2_used 0x0000
#define code_protection_bits 0x3030
#define data_protection_bits 0x0100
char buffer[buffersize];
WORD PIC_HEX_prog_buf[PIC_HEX_PROG_BUF_SIZE];
WORD PIC_HEX_id_buffer[PIC_HEX_ID_BUFFER_SIZE];
WORD PIC_HEX_config_word[PIC_HEX_NR_CONFIG_WORDS];
void program_mode() //puts to program/verify mode
{
output_low(P_DATA);
output_low(P_CLOCK);
output_low(P_MCLR);
delay_us(1);
output_high(P_MCLR);
}
void send_command(unsigned char cmd) //sends a command
{
int i;
output_low(P_CLOCK);
output_low(P_DATA);
output_low(P_MCLR);
delay_us(1);
output_high(P_MCLR);
for(i = 0; i< 6; i++)
{
output_low(P_CLOCK);
if(bit_test(cmd, i))
{
output_high(P_DATA);
}
else
{
output_low(P_DATA);
}
output_high(P_CLOCK);
}
output_low(P_CLOCK);
}
void sendData(unsigned int tempData) //loads 14 bit data when clock cycles 16 times
{
char i;
unsigned char b;
for (i=0; i<16; i++)
{
output_low(P_CLOCK);
if( bit_test(tempData, i))
{
output_high(P_DATA);
}
else
{
output_low(P_DATA);
}
output_high(P_CLOCK);
}
output_low(P_CLOCK);
}
unsigned int readData() //reads a 14bit data word when the clock cycles 16 times
{
char i;
int16 tempData = 0;
for (i = 0; i<16; i++)
{
output_high(P_CLOCK);
if(input(P_DATA))
{
tempData |= 0x8000;
}
else
{
tempData |= 0x0000;
}
output_low(P_CLOCK);
tempData >>= 1;
}
tempData >>= 1;
tempData &= 0x3FFF;
return tempData;
}
void Program_Flash(WORD w) //programs a word
{
sendData(w);
send_command(PIC_CMD_BEGINPROGRAM);
delay_ms(10);
}
void LoadConfig (int base) //loads config
{
int i,n;
send_command(PIC_CMD_LOADCONFIG);
sendData(PIC_HEX_config_word[0]);
n = base - lConfMemBase;
for(i=0;i<n;++i)
{
send_command(PIC_CMD_INCADDRESS);
}
}
BOOL Program(WORD *buf, int n, WORD mask, int loadcmd, int readcmd, int base) //program function
{
int i;
WORD r, w;
WORD wFlags;
int PIC_HEX_ProgMem_LastLoadedAddress;
BOOL still_ok = TRUE;
program_mode();
if ((base >= lConfMemBase) && (base <= lConfWordAdr))
{
LoadConfig(base);
}
for(i=0; i<n; ++i)
{
w=buf[i] & mask;
send_command(loadcmd);
Program_Flash(a);
send_command(PIC_CMD_INCADDRESS);
}
output_low(P_MCLR);
output_low(P_CLOCK);
}
void main()
{
char value;
int i;
WORD w;
int16 storage;
// printf(" Welcome to the PIC programmer\n");
// printf("software was compiled on");
// printf(__DATE__);
// printf("\tat about\t");
//printf(__TIME__);
setup_counters(RTCC_INTERNAL,RTCC_DIV_2);
setup_timer_1(T1_DISABLED);
setup_timer_2(T2_DISABLED,0,1);
enable_interrupts(INT_RDA);
enable_interrupts(global);
program(PIC_HEX_prog_buf, PIC_HEX_ProgMem_LastLoadedAddress+1,0x3FFF,PIC_CMD_LOADPROGRAM,PIC_CMD_READPROGRAM,1);
while(1);
} |
thanks in advance |
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Ttelmah
Guest
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| Posted: Wed Nov 09, 2005 5:57 am |
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Well, without even looking at the program itself, youcannot have these declarations (in fact I'm suprised the compiler does not moan...)
| Code: |
typedef int16 WORD;
#define PIC_HEX_PROG_BUF_SIZE 8192 /* max size of program memory */
WORD PIC_HEX_prog_buf[PIC_HEX_PROG_BUF_SIZE];
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You need to rethink your storage in the local PIC. You should declare a buffer, that is _only_ the size of a 'page' on the target PIC, put a block of data into this, and transfer just this small block 'offset' by a variable that represents the starts of the block in the destination memory.
As it stands, you are trying to define a buffer that is 16384 bytes long, on a PIC that only has 192 bytes of RAM...
Best Wishes |
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PCM programmer
Joined: 06 Sep 2003
Posts: 21708
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| Posted: Wed Nov 09, 2005 2:02 pm |
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| Quote: |
#include <16F873.h>
#use delay(clock=20000000)
#fuses XT,NOWDT,BROWNOUT, PUT, NOLVP |
You're using the XT oscillator setting with a 20 MHz crystal.
It's probably not going to start-up in a reliable way.
You should change it to HS.
Look in the 16F873 data sheet, in the following section, for
a chart which shows the recommended oscillator settings,
based on the crystal frequency:
TABLE 12-2: CAPACITOR SELECTION FOR CRYSTAL OSCILLATOR |
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