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overmindx
Joined: 06 Oct 2008
Posts: 43
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| using 16mb spi flash memory |
 Posted: Tue Mar 02, 2010 4:17 am |
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Hi everybody, I've been trying this to work but to no avail. I am using an AT45db161d 16 mb spi flash memory.
Could somebody with a good heart take a look at my code and see if I am missing something. in the sample code below, even in the part where I want to get the status of the flash memory, located in this function -->int1 RdyBusy(void), it already doesn't work. Using the oscilloscope, I can see that the mcu is sending its command. The problem is that the flash memory is not sending anything.
Here is my code:
| Code: |
#include <18f26k20.h>
#device adc=10
#FUSES WDT32768, INTRC_IO, NOPROTECT, NOIESO, BROWNOUT, PUT, NOCPD, STVREN, NODEBUG, NOLVP, NOWRT, NOWRTD, NOEBTR, NOCPB, NOEBTRB, NOWRTC, NOWRTB, FCMEN, NOXINST, PBADEN, LPT1OSC, MCLR
#use delay(clock=16000000)
#use rs232(baud=19200, xmit=PIN_B4, rcv=PIN_B3, stream=PC)
#include <stdlib.h>
#include <string.h>
#define CS PIN_C2
unsigned char buffer[512];
unsigned char data[512];
void Init(void);
void MemRead(unsigned char *addr,char *buff, unsigned int len);
void MemWrite(unsigned char *addr,char *buff, unsigned int len);
unsigned char WriteSPI(unsigned char data);
char RdyBusy(void);
void SetSizeFT(void);
void main(void){
unsigned long address = 0x00;
unsigned long address2 = 0x00;
char data2[] = {"the quick brown fox jumps over the lazy dog"};
delay_ms(3000);
strcpy(data,data2);
Init();
while(RdyBusy());
delay_ms(200);
address=address<<9;
MemWrite(address,data,512);
while(RdyBusy());
delay_ms(200);
address2=address2<<23;
MemRead(address,buffer,512);
delay_ms(200);
output_high(CS);
while(1){
fprintf(PC,"data buffer = %s\n",buffer);
delay_ms(400);
}
}
void Init(void){
output_high(CS);
setup_spi(SPI_MASTER|SPI_L_TO_H|SPI_CLK_DIV_4);
while(RdyBusy());
SetSizeFT();
}
void MemRead( unsigned char *addr,char *buff, unsigned int len){
unsigned int x;
///CS = 0; //Select the chip
output_low(CS);
spi_write(0x0B); //Continuous Array Read
for( x=0; x<3; x++) //Send the Address (Page & Byte Start Address)
spi_write(*addr++);
spi_write(0xFF);
for( x=0; x<len; x++) //Read the Data In (Clock it)
*buff++ = spi_read();
///CS = 1; //DeSelect the Chip
output_high(CS);
}
void MemWrite( unsigned char *addr,char *buff, unsigned int len){
int x;
///CS = 0; //Select the chip
output_low(CS);
spi_write(0x84); //Buffer Write
for( x=0; x<3; x++) //Send the Address (Page & Byte Start Address)
spi_write(0x00);
for( x=0; x<len; x++) //Send the 4 Dont Care Bytes
spi_write(*buff++);
///CS = 1; //DeSelect the Chip
output_high(CS);
/////////////////////////////////////////////////////////////////////////////
/////////////////////////////////////////////////////////////////////////////
///CS = 0; //Select the chip
output_low(CS);
spi_write(0x83); //Buffer Write
for( x=0; x<3; x++) //Send the Address (Page & Byte Start Address)
spi_write(*addr++);
for( x=0; x<len; x++) //Send the 4 Dont Care Bytes
spi_write(*buff++);
////CS = 1; //DeSelect the Chip
output_high(CS);
}
int1 RdyBusy(void){
int wait=0;
output_low(CS);
spi_write(0xD7);
spi_write(0xD7);
wait = spi_read(0);
///CS = 1; //DeSelect the Chip
output_high(CS);
fprintf(PC,"wait=%i\n",wait); // PROBLEM HERE!! THE WAIT INTEGER ALWAYS RETURNS 0....
if(wait != 0)
return 0;
else
return 1;
}
void SetSizeFT(void){ //Five Twelve (512)
unsigned char stat;
///CS = 0; //Select the chip
output_low(CS);
spi_write(0x3D);
spi_write(0x2A);
spi_write(0x80);
spi_write(0xA6);
///CS = 1; //DeSelect the Chip
output_high(CS);
}
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My circuit is similar to this
http://atomsoft.files.wordpress.com/2010/02/16mbitschem.jpg
However, I use 18f26k20 instead of the one shown in the picture.
Please help me figure out whats wrong with my program. Thanks. |
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ckielstra
Joined: 18 Mar 2004
Posts: 3680
Location: The Netherlands
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| Posted: Tue Mar 02, 2010 5:35 pm |
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This chip works in either SPI mode 0 or 3 (see chapter 3 of the datasheet). You are using mode 1.
For easier setup use the following defines: | Code: | #define SPI_MODE_0 (SPI_L_TO_H | SPI_XMIT_L_TO_H)
#define SPI_MODE_1 (SPI_L_TO_H)
#define SPI_MODE_2 (SPI_H_TO_L)
#define SPI_MODE_3 (SPI_H_TO_L | SPI_XMIT_L_TO_H) |
And then change the setup to: | Code: | | setup_spi(SPI_MASTER| SPI_MODE_0 |SPI_CLK_DIV_4); |
Another problem is that the spi_read() function only generates a clock when you add a parameter value. Change | Code: | | *buff++ = spi_read(); |
to: | Code: | | *buff++ = spi_read(0); |
What is your compiler version number? |
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x!nDy
Guest
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| Posted: Tue Mar 02, 2010 9:17 pm |
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| Hello, thanks for the reply. I have done what you recommend but it still won't work...even in the part where I just want to get the status of the flash memory, it wont send back its status. My compiler version is PCH v.4.096. Please help. |
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overmindx
Joined: 06 Oct 2008
Posts: 43
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| Posted: Tue Mar 02, 2010 10:17 pm |
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Hello, using an oscilloscope, I checked the SO pin (PIN_C5). It seems the voltage spikes it generates are just a few mV. But when I changed
| Code: |
setup_spi(SPI_MASTER|SPI_L_TO_H|SPI_CLK_DIV_4)
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to
| Code: |
setup_spi(SPI_MASTER|SPI_L_TO_H|SPI_XMIT_L_TO_H|SPI_CLK_DIV_64)
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the voltage spikes became 2 volts. Is this a good enough voltage already for the flash memory to properly receive the command? Or am I missing something here? Please help. |
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