Fix #17 - pulse both CE and OE during the write verify cycle.

TommyPROM/PromDevice.cpp

@@ -66,6 +66,22 @@ bool PromDevice::writeData(byte data[], uint32_t len, uint32_t address)
     return status;
 }
 
+void PromDevice::resetDebugStats() {
+    debugBlockWrites = 0;
+    debugLastAddress = 0;
+    debugLastExpected = 0;
+    debugLastReadback = 0;
+}
+void PromDevice::printDebugStats() {
+    Serial.print(F("debugBlockWrites:  "));
+    Serial.println(debugBlockWrites);
+    Serial.print(F("debugLastAddress:  "));
+    Serial.println(debugLastAddress, HEX);
+    Serial.print(F("debugLastExpected: "));
+    Serial.println(debugLastExpected, HEX);
+    Serial.print(F("debugLastReadback: "));
+    Serial.println(debugLastReadback, HEX);
+}
 
 // BEGIN PRIVATE METHODS
 //
@@ -105,5 +121,3 @@ void PromDevice::writeDataBus(byte data)
      PORTB = (PORTB & 0xfc) | (data >> 6);
      PORTD = (PORTD & 0x03) | (data << 2);
 }
-
-

TommyPROM/PromDevice.h

@@ -20,6 +20,8 @@ class PromDevice
     PromDevice(uint32_t size, word blockSize, unsigned maxWriteTime, bool polling);
     bool writeData(byte data[], uint32_t len, uint32_t address);
     byte readData(uint32_t address) { return readByte(address); }
+    void resetDebugStats();
+    void printDebugStats();
 
     virtual void begin() = 0;
     virtual const char * getName() = 0;
@@ -32,6 +34,11 @@ class PromDevice
     unsigned int mMaxWriteTime;     // Max time (in ms) to wait for write cycle to complete
     bool mSupportsDataPoll;         // End of write detected by data polling
 
+    uint32_t debugBlockWrites;      // Number of block write operations
+    uint32_t debugLastAddress;      // Last address with an issue
+    uint8_t  debugLastExpected;     // Last expected readback value
+    uint8_t  debugLastReadback;     // Last actual readback value
+
     void setDataBusMode(uint8_t mode);
     byte readDataBus();
     void writeDataBus(byte data);
@@ -45,4 +52,3 @@ class PromDevice
 
 
 #endif  // #define INCLUDE_PROM_DEVICE_H
-

TommyPROM/PromDevice28C.cpp

@@ -138,9 +138,9 @@ bool PromDevice28C::burnByte(byte value, uint32_t address)
 bool PromDevice28C::burnBlock(byte data[], uint32_t len, uint32_t address)
 {
     bool status = false;
-
     if (len == 0)  return true;
 
+    ++debugBlockWrites;
     disableOutput();
     disableWrite();
     enableChip();
@@ -162,6 +162,9 @@ bool PromDevice28C::burnBlock(byte data[], uint32_t len, uint32_t address)
     status = waitForWriteCycleEnd(data[len - 1]);
     disableChip();
 
+    if (!status) {
+        debugLastAddress = address + len - 1;
+    }
     return status;
 }
 
@@ -174,29 +177,36 @@ bool PromDevice28C::waitForWriteCycleEnd(byte lastValue)
         // value written twice in a row.  The D7 bit will read the inverse of last written
         // data and the D6 bit will toggle on each read while in programming mode.
         //
-        // Note that the max readcount is set to the device's maxReadTime (in uSecs)
-        // divided by two because there are two 1 uSec delays in the loop.  In reality,
-        // the loop could run for longer because this does not account for the time needed
-        // to run all of the loop code.  In actual practice, the loop will terminate much
+        // This loop code takes about 18uSec to execute.  The max readcount is set to the
+        // device's maxReadTime (in uSecs) divided by ten rather than eighteen to ensure
+        // that it runs at least as long as the chip's timeout value, even if some code
+        // optimizations are made later. In actual practice, the loop will terminate much
         // earlier because it will detect the end of the write well before the max time.
+        byte b1=0, b2=0;
         setDataBusMode(INPUT);
         delayMicroseconds(1);
-        for (int readCount = mMaxWriteTime * 1000 / 2; (readCount > 0); readCount--)
+        for (int readCount = 1; (readCount < (mMaxWriteTime * 100)); readCount++)
         {
+            enableChip();
             enableOutput();
             delayMicroseconds(1);
-            byte b1 = readDataBus();
+            b1 = readDataBus();
             disableOutput();
+            disableChip();
+            enableChip();
             enableOutput();
             delayMicroseconds(1);
-            byte b2 = readDataBus();
+            b2 = readDataBus();
             disableOutput();
+            disableChip();
             if ((b1 == b2) && (b1 == lastValue))
             {
                 return true;
             }
         }
 
+        debugLastExpected = lastValue;
+        debugLastReadback = b2;
         return false;
     }
     else
@@ -224,4 +234,3 @@ void PromDevice28C::setByte(byte value, uint32_t address)
 }
 
 #endif // #if defined(PROM_IS_28C)
-

TommyPROM/TommyPROM.ino

@@ -19,7 +19,7 @@
 #include "XModem.h"
 
 
-static const char * MY_VERSION = "2.3";
+static const char * MY_VERSION = "2.4";
 
 
 // Global status
@@ -84,6 +84,7 @@ enum {
     CMD_UNLOCK,
     CMD_WRITE,
 
+    CMD_INFO,
     CMD_SCAN,
     CMD_TEST,
     CMD_ZAP,
@@ -142,6 +143,7 @@ byte parseCommand(char c)
         case 'u':  cmd = CMD_UNLOCK;    break;
         case 'w':  cmd = CMD_WRITE;     break;
 
+        case 'i':  cmd = CMD_INFO;      break;
         case 's':  cmd = CMD_SCAN;      break;
         case 't':  cmd = CMD_TEST;      break;
         case 'z':  cmd = CMD_ZAP;       break;
@@ -583,7 +585,6 @@ void zapTest(uint32_t start)
         0x00, 0xff, 0x55, 0xaa, '0',  '1',  '2',  '3'
     };
 
-
     if (!prom.writeData(testData, sizeof(testData), start))
     {
         cmdStatus.error("Write failed");
@@ -676,6 +677,7 @@ void loop()
         break;
 
     case CMD_FILL:
+        prom.resetDebugStats();
         fillBlock(start, end, val);
         break;
 
@@ -685,6 +687,7 @@ void loop()
         break;
 
     case CMD_POKE:
+        prom.resetDebugStats();
         pokeBytes(line+1);
         break;
 
@@ -703,6 +706,7 @@ void loop()
         break;
 
     case CMD_WRITE:
+        prom.resetDebugStats();
         Serial.println(F("Send the image file using XMODEM CRC"));
         numBytes = xmodem.ReceiveFile(start);
         if (numBytes)
@@ -717,6 +721,10 @@ void loop()
         break;
 
 #ifdef ENABLE_DEBUG_COMMANDS
+    case CMD_INFO:
+        prom.printDebugStats();
+        break;
+
     case CMD_SCAN:
         scanBlock(start, end);
         break;
@@ -726,6 +734,7 @@ void loop()
         break;
 
     case CMD_ZAP:
+        prom.resetDebugStats();
         zapTest(start);
         break;
 #endif /* ENABLE_DEBUG_COMMANDS */
@@ -752,6 +761,7 @@ void loop()
         Serial.println(F("  Wsssss          - Write to device from XMODEM CRC file"));
 #ifdef ENABLE_DEBUG_COMMANDS
         Serial.println();
+        Serial.println(F("  I               - Print debug Info"));
         Serial.println(F("  Ssssss eeeee    - Scan addresses (read each 10x)"));
         Serial.println(F("  Tsssss          - Test read address (read 100x)"));
         Serial.println(F("  Zsssss          - Zap (burn) a 32 byte test pattern"));