Dram Tester

# includes

#define DI 15 // PC1
#define DO 8 // PB0
#define CAS 9 // PB1
#define RAS 17 // PC3
#define WE 16 // PC2

#define XA0 18 // PC4
#define XA1 2 // PD2
#define XA2 19 // PC5
#define XA3 6 // PD6
#define XA4 5 // PD5
#define XA5 4 // PD4
#define XA6 7 // PD7
#define XA7 3 // PD3
#define XA8 14 // PC0

#define M_TYPE 10 // PB2
#define R_LED 11 // PB3
#define G_LED 12 // PB4

#define RXD 0 // PD0
#define TXD 1 // PD1

#define BUS_SIZE 9 // set to 7 if used for 4116

volatile int bus_size;

// SoftwareSerial USB (RXD, TXD);

const unsigned int a_bus [BUS_SIZE] = {
XA0, XA1, XA2, XA3, XA4, XA5, XA6, XA7, XA8
};

void setBus (unsigned int a) {
int i;

// correct function

for (i = 0; i <bus_size; i ++) {

    if (bitRead (a, i) == 1) {
      digitalWrite (a_bus [i], HIGH);
    } else {
      digitalWrite (a_bus [i], LOW);
    }
  }
}

void writeAddress (unsigned int r, unsigned int c, int v) {
/ * row * /
setBus (r);
digitalWrite (RAS, LOW);

/ * rw * /
digitalWrite (WE, LOW);

/ * val * /
digitalWrite (DI, (v & 1)? HIGH: LOW);

/* with the */
setBus (c);
digitalWrite (CAS, LOW);

digitalWrite (WE, HIGH);
digitalWrite (CAS, HIGH);
digitalWrite (RAS, HIGH);
}

int readAddress (unsigned int r, unsigned int c) {
int ret = 0;

/ * row * /
setBus (r);
digitalWrite (RAS, LOW);

/* with the */
setBus (c);
digitalWrite (CAS, LOW);

/ * get current value * /
ret = digitalRead (DO);

digitalWrite (CAS, HIGH);
digitalWrite (RAS, HIGH);

return ret;
}

void error (int r, int c)
{
unsigned long a = ((unsigned long) c << bus_size) + r;
digitalWrite (R_LED, LOW);
digitalWrite (G_LED, HIGH);
interrupts ();
Serial.print ("FAILED $");
Serial.println (a, HEX);
Serial.flush ();
while (1)
;
}

void ok (void)
{
digitalWrite (R_LED, HIGH);
digitalWrite (G_LED, LOW);
interrupts ();
Serial.println ("OK!");
Serial.flush ();
while (1)
;
}

void blink (void)
{
digitalWrite (G_LED, LOW);
digitalWrite (R_LED, LOW);
delay (1000);
digitalWrite (R_LED, HIGH);
digitalWrite (G_LED, HIGH);
}

void green (int v) {
digitalWrite (G_LED, v);
}

void fill (int v) {
int r, c, g = 0;
v % = 1;
for (c = 0; c <(1 < <bus_size); c++) {
green (g? HIGH: LOW);
for (r = 0; r <(1 < <bus_size); r++) {
writeAddress (r, c, v);
if (v! = readAddress (r, c))
error (r, c);
}
g ^ = 1;
}
blink ();
}

void fillx (int v) {
int r, c, g = 0;
v % = 1;
for (c = 0; c <(1 < <bus_size); c++) {
green (g? HIGH: LOW);
for (r = 0; r <(1 < <bus_size); r++) {
writeAddress (r, c, v);
if (v! = readAddress (r, c))
error (r, c);
v ^ = 1;
}
g ^ = 1;
}
blink ();
}

void setup () {
int i;

Serial.begin (9600);
while (! Serial)
; / * wait * /

Serial.println ();
Serial.print ("DRAM TESTER");

for (i = 0; i <BUS_SIZE; i ++)
pinMode (a_bus [i], OUTPUT);

pinMode (CAS, OUTPUT);
pinMode (RAS, OUTPUT);
pinMode (WE, OUTPUT);
pinMode (DI, OUTPUT);

pinMode (R_LED, OUTPUT);
pinMode (G_LED, OUTPUT);

pinMode (M_TYPE, INPUT);
pinMode (DO, INPUT);

digitalWrite (WE, HIGH);
digitalWrite (RAS, HIGH);
digitalWrite (CAS, HIGH);

digitalWrite (R_LED, HIGH);
digitalWrite (G_LED, HIGH);

// if using memory 4146 don't insert this loop if (digitalRead)… else ..

if (digitalRead (M_TYPE)) {
/ * jumper not set - 41256 * /
bus_size = BUS_SIZE;
Serial.print ("256Kx1");
} else {
/ * jumper set - 4164 * /
bus_size = BUS_SIZE - 1;
Serial.print ("64Kx1");
}

Serial.flush ();

digitalWrite (R_LED, LOW);
digitalWrite (G_LED, LOW);

noInterrupts ();
for (i = 0; i <(1 << BUS_SIZE); i ++) {
digitalWrite (RAS, LOW);
digitalWrite (RAS, HIGH);
}
digitalWrite (R_LED, HIGH);
digitalWrite (G_LED, HIGH);
}

void loop () {
interrupts (); Serial.print (“.”); Serial.flush (); noInterrupts (); fillx (0);
interrupts (); Serial.print (“.”); Serial.flush (); noInterrupts (); fillx (1);
interrupts (); Serial.print (“.”); Serial.flush (); noInterrupts (); fill (0);
interrupts (); Serial.print (“.”); Serial.flush (); noInterrupts (); fill (1);
ok ();
}