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Hello everybody,
This is my first post on the Altera Forums, and i have to say it's been quite helpfull to me the last few months, so thanks for that.
This is my situation:
I need to send and recieve messages via the CAN interface with the MCP2515 chip.
I've done the Quartus block diagram which includes the NIOS 2 processor, an SDRAM from the Deo-Nano board, and an SPI interface with which to communicate with the CAN controller, and everything works perfectly (no timing errors or nothing).
So basically, i just need help with the C coding using alt_avalon_spi_command. i'll just show my code and you give oppinions if you'd like.
void RESET ()
{
unsigned char command;
command=0x30;
alt_avalon_spi_command(SPI_BASE,0,1,command,0,NULL,0);
}
unsigned char READ_RX_BUFF (unsigned char reg)
{
//00 RXB0SIDH
//01 RXB0D0
//02 RXB1SIDH
//03 RXB0D1
unsigned char rdata,rdata1,command;
unsigned char data_out;
unsigned int i;
command=(1<<7) | (1<<4) | (reg<<1);
printf("\n%d ",command);
for (i=0; i<8; i++)
{
rdata=0 ;
rdata1=0 ;
data_out=0;
}
if ((reg==0) || (reg==2))
{
alt_avalon_spi_command(SPI_BASE,0,1,command,5,rdata,0);
for (i=0; i<5; i++)
{
data_out= rdata ;
printf("%x ",data_out);
}
}
if ((reg==1) || (reg==3))
{
alt_avalon_spi_command(SPI_BASE,0,1,command,8,rdata1,0);
for (i=0; i<8; i++)
{
data_out= rdata1 ;
printf("%x ",data_out);
}
}
return *data_out;
}
void SPI_WRITE(alt_u8 adress, alt_u8 message)
{
unsigned char command;
command=0x02;
alt_avalon_spi_command(SPI_BASE,0,1,command,0,NULL,0);
alt_avalon_spi_command(SPI_BASE,0,1,&adress,0,NULL,0);
alt_avalon_spi_command(SPI_BASE,0,1,&message,0,NULL,0);
}
unsigned char SPI_READ(alt_u8 adress)
{
unsigned char command;
unsigned char read;
unsigned char data_out;
command=0x03;
read=0;
alt_avalon_spi_command(SPI_BASE,0,1,command,0,NULL,0);
alt_avalon_spi_command(SPI_BASE,0,1,&adress,1,read,0);
data_out=read;
return data_out;
}
void SPI_LOAD_TX(long int message, alt_u8 reg)
{
//reg 0x0 TXB0SIDH
//reg 0x1 TXB0D0
//reg 0x2 TXB1SIDH
//reg 0x3 TXB0D1
//reg 0x4 TXB2SIDH
//reg 0x5 TXB1D2
unsigned char message1,command; ////read byte 0x04
int i;
command=(1<<6)|reg;
alt_avalon_spi_command(SPI_BASE,0,1,command,0,NULL,0);
if ((reg==0x00) || (reg==0x02) || (reg==0x4))
{
for (i=0; i<5; i++)
{ message=message>>(i*8);
message1=message & 0xff;
alt_avalon_spi_command(SPI_BASE,0,1,message1,0,NULL,0);
}
}
if ((reg==0x01) || (reg==0x03) || (reg==0x5))
{
for (i=0; i<8; i++)
{ message=message>>(i*8);
message1=message & 0xff;
alt_avalon_spi_command(SPI_BASE,0,1,message1,0,NULL,0);
}
}
}
void RTS(alt_u8 reg)
{
//reg 0x00 T1
//reg 0x02 T2
//reg 0x04 T3
unsigned char command;
command=(0x01<<7) | reg;
alt_avalon_spi_command(SPI_BASE,0,1,command,0,NULL,0);
}
void BIT_MODIFY(alt_u8 adress, alt_u8 mask, alt_u8 data)
{
unsigned char command;
command=0x05;
alt_avalon_spi_command(SPI_BASE,0,1,command,0,NULL,0);
alt_avalon_spi_command(SPI_BASE,0,1,&adress,0,NULL,0);
alt_avalon_spi_command(SPI_BASE,0,1,&mask,0,NULL,0);
alt_avalon_spi_command(SPI_BASE,0,1,&data,0,NULL,0);
}
void SPEED_RATE(alt_u8 rate)
{
if (rate==10)
{
BIT_MODIFY(CNF1,0xff,0x31); //CNF1
BIT_MODIFY(CNF2,0xff,0xb8); //CNF2
BIT_MODIFY(CNF3,0xff,0x05); //CNF3
}
if (rate==20)
{
BIT_MODIFY(CNF1,0xff,0x18); //CNF1
BIT_MODIFY(CNF2,0xff,0xb8); //CNF2
BIT_MODIFY(CNF3,0xff,0x05); //CNF3
}
if (rate==50)
{
BIT_MODIFY(CNF1,0xff,0x09); //CNF1
BIT_MODIFY(CNF2,0xff,0xb8); //CNF2
BIT_MODIFY(CNF3,0xff,0x05); //CNF3
}
if (rate==100)
{
BIT_MODIFY(CNF1,0xff,0x04); //CNF1
BIT_MODIFY(CNF2,0xff,0xb8); //CNF2
BIT_MODIFY(CNF3,0xff,0x05); //CNF3
}
if (rate==125)
{
BIT_MODIFY(CNF1,0xff,0x03); //CNF1
BIT_MODIFY(CNF2,0xff,0xb8); //CNF2
BIT_MODIFY(CNF3,0xff,0x05); //CNF3
}
if (rate==250)
{
BIT_MODIFY(CNF1,0xff,0x01); //CNF1
BIT_MODIFY(CNF2,0xff,0xb8); //CNF2
BIT_MODIFY(CNF3,0xff,0x05); //CNF3
}
if (rate==500)
{
BIT_MODIFY(CNF1,0xff,0x00); //CNF1
BIT_MODIFY(CNF2,0xff,0xb8); //CNF2
BIT_MODIFY(CNF3,0xff,0x05); //CNF3
}
}
void CONFIG_STATE(char state)
{
if (state==1)
{
//CANCTRL status config
BIT_MODIFY(CANCTRL,0xff,MODE_CONFIG); //configuration mode
SPEED_RATE(100); //speed rate 100kbps
BIT_MODIFY(0x2b,0xff,0x00); //CANINTE clear
BIT_MODIFY(0x2c,0xff,0x00); //CANINTF clear
//BFPCTRL set
BIT_MODIFY(0x0c,0xff,0x0f); // RXnBF set as interrupt pin(0x0f)
BIT_MODIFY(RXB0CTRL,0xff,0x60); // Write to RXB0CTRL and set masks and filters off
BIT_MODIFY(RXB1CTRL,0xff,0x60); // Write to RXB1CTRL and set masks and filters off
//RX BUFFER 0
BIT_MODIFY(RXM0SIDH,0xff,0x00); // RXM0SIDH clear
BIT_MODIFY(RXM0SIDL,0xff,0x00); // RXM0SIDL clear
BIT_MODIFY(RXM0EID8,0xff,0x00); // RXM0EID8 clear
BIT_MODIFY(RXM0EID0,0xff,0x00); // RXM0EID0 clear
//RX BUFFER 1
BIT_MODIFY(RXM1SIDH,0xff,0x00); // RXM1SIDH clear
BIT_MODIFY(RXM1SIDL,0xff,0x00); // RXM1SIDL clear
BIT_MODIFY(RXM1EID8,0xff,0x00); // RXM1EID8 clear
BIT_MODIFY(RXM1EID0,0xff,0x00); // RXM1EID0 clear
//TXRTSCTRL set
BIT_MODIFY(0x0d,0xff,0x01); // request to send from txb0 (0x01)
BIT_MODIFY(0x2D,0xff,0x00); // clear EFLG
}
if (state==2)
{
BIT_MODIFY(CANCTRL,0xff,MODE_LISTEN); //listen mode
}
if (state==3)
{
BIT_MODIFY(CANCTRL,0xff,MODE_LOOPBACK); //loopback mode
}
if (state==4)
{
BIT_MODIFY(CANCTRL,0xff,MODE_SLEEP); //sleeep mode
}
if (state==5)
{
BIT_MODIFY(CANCTRL,0xff,MODE_NORMAL); //normal mode
}
}
int main()
{unsigned long int delay;
unsigned char radu,radu1;
RESET();
CONFIG_STATE(1);
CONFIG_STATE(5);
while(1)
{delay=0;
while (delay<200000)
{delay++;}
y=READ_RX_BUFF(1);
SPI_WRITE(0x61,0x05);
x=SPI_READ(0x61);
printf(" %d %d ",y,x);
}
}
of course this includessome Macros declarations in a separate file.
So the problem is this. What am I doing wrong :)
thanks if you read, and sorry for the bad english.
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Hi, Pallys,
Have you found an answer?
I'm currently working on the same connection (Nios/MCP2515).
I've learned from the datasheet that you cannot use BIT_MODIFY on all registers.
You need to do an SPI_WRITE instead.
Also, the minimum registers you need to write to are TXBnSIDH, TXBnSIDL and TXBnDLC before performing an RTS.
From your comments, I can see you do not consider the last two, although you consider the data register TXBnDm.
I think that before you send any data using TXBnDm you should, first, send only a message with headers, which will require less SPI tranmissions, thus rendering the process less prone to errors.
Well, let me know if you could make it work.
Thanks,
Lucas.
Honored Contributor
