Leer y escribir memoria 93CSeries Microwire EEPROM con Arduino.

Bienvenidos a esta nueva entrada. Os pongo el código de arduino para leer y escribir una memoria EEPROM a través del protocolo Microwire, que es una variacion del protocolo SPI.

El sketch de arduino está disponible para su descarga aquí.

Saludos!

/****************************************************

 ********CREATED BY INGENIERIA EN CASA***************

 **********10.03.2016********************************

 *********EEPROM READER/WRITER 93C56 SERIES**********

 ****************************************************

 */

#define PIN_CLK 8   //PIN TO SEND CLOCK SIGNAL

#define PIN_ORG 12  //PIN TO SELECT BYTE OR WORD

#define PIN_S 9     //PIN CHIP SELECT

#define PIN_D 10    //PIN DATA INPUT

#define PIN_Q 11    //PIN DATA OUTPUT

#define MEMORY_SIZE 256   //Size in bytes

byte dataOutput[MEMORY_SIZE];   //variable to store data 

/*shift out 12 bits*/

void shift12bits(unsigned int data){

  digitalWrite(PIN_S,HIGH);       //CHIP SELECT HIGH TO ACTIVATE CHIP

  for(byte count = 0; count < 12; count ++){

    digitalWrite(PIN_CLK,LOW);    //PIN CLOCK LOW TO MAKE AFTER SETTING DATA THE TRANSITION

    if(data & 0x0800)             //MSB FIRST  0x0800 '0b 0000 1000 0000 0000

      digitalWrite(PIN_D,HIGH);

    else 

      digitalWrite(PIN_D,LOW);

    digitalWrite(PIN_CLK,LOW);

    digitalWrite(PIN_CLK,HIGH);   //CLOCK PULSE

    data <<= 1;                   //rotate left to prepare for next bit

  }

}

/*shift out data*/

void shiftdata(byte data_write){

  for(byte count = 0; count < 8; count ++){

    digitalWrite(PIN_CLK,LOW);    //PIN CLOCK LOW TO MAKE AFTER SETTING DATA THE TRANSITION

    if(data_write & 0x80)             //MSB FIRST  0x0800 '0b 0000 1000 0000 0000

      digitalWrite(PIN_D,HIGH);

    else 

      digitalWrite(PIN_D,LOW);

    digitalWrite(PIN_CLK,LOW);

    digitalWrite(PIN_CLK,HIGH);   //CLOCK PULSE

    data_write <<= 1;                   //rotate left to prepare for next bit

  }

}

/*get output from chip*/

void getOutput(byte address_local){

  for(byte i = 0; i < 8; i++){

    digitalWrite(PIN_CLK,LOW);

    digitalWrite(PIN_CLK,HIGH);   //rising edge of clock pin is when data is latched out

    if(digitalRead(PIN_Q))

      dataOutput[address_local] |= 1 << (7-i);  //get msb first. when i = 0, we get 0bX0000000

  }

  digitalWrite(PIN_S,LOW);       //CHIP SELECT LOW TO DEACTIVATE CHIP

}

/*reads the whole memory*/

void read_all(void){

  //start bit = 1

  //read op code = 10

  //Address A8-A0  (A8 not decoded in 93C56WP) 

  //variable address store A7-A0

  unsigned int full_address = 0x0000;

  for(unsigned int address = 0; address < MEMORY_SIZE; address ++){

    full_address = 1 << 11 | 1 << 10 | (byte)address;   //create address with start bit and op code  0b 0000 110X AAAA AAAA

    shift12bits(full_address);

    //while(digitalRead(PIN_Q)){};                  //wait until first dummy 0 is sent by chip

    getOutput(address);

    Serial.print("Adress:");

    Serial.print(address,HEX);

    Serial.print("--");

    Serial.print("Data:");

    Serial.println(dataOutput[address],HEX);

    //delay(50);

  }

}

void write_byte(byte address_write,byte data_write){

  //mask for writing 0b 0000 101X AAAA AAAA

  unsigned int write_mask = 0x0A00 | (byte)address_write;

  shift12bits(write_mask);

  shiftdata(data_write);

  digitalWrite(PIN_S,LOW);                    //CHIP SELECT LOW TO DEACTIVATE CHIP

  digitalWrite(PIN_S,HIGH);                   //BEGIN CHECK STATUS

  while(digitalRead(PIN_Q) == LOW){};         //WAIT UNTIL READY

  digitalWrite(PIN_S,LOW);                    //END CHECK STATUS

  

}

void ew_enable(void){

  unsigned int ew_enable_mask = 0x0980;       //0b0000 1001 1XXX XXXX

  shift12bits(ew_enable_mask);                //send enable write erase mask

  digitalWrite(PIN_S,LOW);                    //CHIP SELECT LOW TO DEACTIVATE CHIP

}

void ew_disable(void){

  unsigned int ew_disable_mask = 0x0800;       //0b0000 1000 0XXX XXXX

  shift12bits(ew_disable_mask);                //send disable write erase mask

  digitalWrite(PIN_S,LOW);                     //CHIP SELECT LOW TO DEACTIVATE CHIP

}

void erase_all(void){

  unsigned int erase_all_mask = 0x0900;       //0b0000 1001 0XXX XXXX

  shift12bits(erase_all_mask);                //send enable write erase mask

  digitalWrite(PIN_S,LOW);                    //CHIP SELECT LOW TO DEACTIVATE CHIP

  digitalWrite(PIN_S,HIGH);                   //BEGIN CHECK STATUS

  while(digitalRead(PIN_Q) == LOW){};         //WAIT UNTIL READY

  digitalWrite(PIN_S,LOW);                    //END CHECK STATUS

}

void setup() {

  // put your setup code here, to run once:

  pinMode(PIN_CLK,OUTPUT);

  pinMode(PIN_ORG,OUTPUT);

  pinMode(PIN_S,OUTPUT);

  pinMode(PIN_D,OUTPUT);

  pinMode(PIN_Q,INPUT);

  digitalWrite(PIN_ORG,LOW);    //ORG = 0 (x8 origination) byte read or write

  digitalWrite(PIN_S,LOW);      //standby state of chip select pin  

  digitalWrite(PIN_CLK,LOW);    //initialize pin clk to low

  Serial.begin(9600);

//  read_all();

//  ew_enable();

//  //erase_all();

//  for(unsigned int counter = 0; counter < MEMORY_SIZE; counter ++)

//  write_byte((byte)counter,MEMORY_SIZE-1-(byte)counter);//write_byte(byte address, byte data);

//  ew_disable();

  read_all();

}

void loop() {

  // put your main code here, to run repeatedly:

}