Svenska ElektronikForumet

Kod: Markera allt

CON                                                       
  _clkmode = xtal1 + pll16x ' PLL
  _xinfreq = 5_000_000      ' Crystal 5 MHz
                            ' 16*5 = µC 80MHz (PASM: Instruction =>4 Clocks. SPIN: Very slow)
  SI  = 0                   ' Serial Data Input
  SCK = 1                   ' Serial Clock
  SO  = 2                   ' Serial Data Output
  CE  = 3                   ' Chip Enable
  LED_DEBUG = 4             ' Led             
  GND       = 5             ' Led -> GND                
  PIN_MASK = 1<<SI | 1<<SCK | 1<<CE | 1<<LED_DEBUG | 1<<GND

PUB Main
  Init                          ' Set pin and initialize SCK   
  WREN                          ' Enable Write Enable Latch
  if WREN_Check                 ' WEL check
    outa[LED_DEBUG]~~
    
  repeat                                 
                                                                  
PUB Init                                                           
  dira |= PIN_MASK              ' Set output       
  outa[SCK] := 0                ' Set clock to low initial state

PUB WREN
'' This procedure enables the Write Enable Latch.
'' It can also be used to Enables Write Status Register.
  outa[CE] := 0                 ' Enable device, clear CE low
  Send_Byte($06)                ' Send WREN command 
  outa[CE] := 1                 ' Disable device, set CE high 

PUB WREN_Check | byte_
'' This procedure checks to see if WEL bit set before program/erase.
  byte_ := Read_Status_Register ' Read the status register  
  if byte_ == $02               ' Verify that WEL bit is set
    result := true      
  else                  
    result := false    
                        ' add source code or statements for this file to compile
                        ' i.e. option: insert a display to view error on LED? 
                        
PUB Read_Status_Register | byte_          
  outa[CE] := 0                 ' Enable device, clear CE low
  Send_Byte($05)                ' Send RDSR command 
  byte_ := Get_Byte             ' Receive byte 
  outa[CE] := 1                 ' Disable device, set CE high 
  result := byte_
  
PRI Send_Byte(out) | i
  repeat i from 0 to 7          ' for (i = 0 i < 8 i++)    
    if (out & $80) == $80       ' check if MSB is high 
      outa[SI] := 1
    else
      outa[SI] := 0             ' if not, set to low            
    outa[SCK] := 1              ' toggle clock high   
    out := (out << 1)           ' shift 1 place for next bit    
    outa[SCK] := 0              ' toggle clock low   
    
PRI Get_Byte | i,in,temp
  in := 0
  repeat i from 0 to 7          ' for (i = 0 i < 8 i++)  
    in := (in << 1)             ' shift 1 place to the left or shift in 0 
    temp := ina[SO]             ' save input 
    outa[SCK] := 1              ' toggle clock high 
    if temp == 1                ' check to see if bit is high 
      in := in | $01            ' if high, make bit high
    outa[SCK] := 0              ' toggle clock low           
  result := in
                                                  

Kod: Markera allt

#include <avr/io.h>

#define DDR_SPI   DDRB
#define PORT_SPI  PORTB
#define DD_CE     PORTB2
#define DD_MOSI   PORTB3
#define DD_SCK    PORTB5

void SPI_MasterInit(void);
char SPI_MasterTransmit(char);
void CE_High(void);
void CE_Low(void);
void WREN(void);
unsigned char RDSR();
void WREN_Check(void);



int main()
{
	SPI_MasterInit(); //Initiate SPI Master
	WREN(); //Write Enable
	WREN_Check(); //Lights a LED if Write is enabled
}

void SPI_MasterInit(void)
{
	// Set MOSI and SCK output, all others input
	DDR_SPI = (1<<DD_MOSI)|(1<<DD_SCK)|(1<<DD_CE);
	// Enable SPI, Master, set clock rate fck/16
	SPCR = (1<<SPE)|(1<<MSTR)|(1<<SPR0);
	// Make sure that CE is high(device disabled)
	PORT_SPI |= (1<<DD_CE);
}

char SPI_MasterTransmit(char data)
{
	// Start transmission
	SPDR = data;
	// Wait for transmission complete
	while(!(SPSR & (1<<SPIF)));
	// Return the received byte
	return (SPDR);
}

void CE_High(void)
{
	PORT_SPI |= (1<<DD_CE);
}

void CE_Low(void)
{
	PORT_SPI &= ~(1<<DD_CE);
}

void WREN(void)
{
	CE_Low();
	SPI_MasterTransmit(0x06);
	CE_High();
}


unsigned char RDSR()
{
	unsigned char byte = 0;
	CE_Low();
	byte = SPI_MasterTransmit(0x05);
	CE_High();
	return (byte);
}


void WREN_Check(void)
{
	unsigned char status = 0;
	status = RDSR();
	if (status != 0x02)
	{
		PORTB |= (1<<0);
	}else{
		PORTB &= ~(1<<0);
	}
}