Arduino-Based AT28C256 EEPROM Programmer.

Initial commit with working reads and full dumps.

.gitignore

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+.idea/

LICENSE

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+Copyright 2019, Erik van Zijst <[email protected]>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.

adruino/adruino.ino

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+/*
+ * AT28C256 EEPROM Reader and Programmer
+ * 
+ * This code implements the serial wire protocol as described in protocol.txt
+ * 
+ * Pin Layout
+ * 
+ * Pin | Circuit
+ * ----+--------------
+ *   2 | EEPROM IO0
+ *   3 | EEPROM IO1
+ *   4 | EEPROM IO2
+ *   5 | EEPROM IO3
+ *   6 | EEPROM IO4
+ *   7 | EEPROM IO5
+ *   8 | EEPROM IO6
+ *   9 | EEPROM IO7
+ * ----+--------------
+ *  10 | 74HC595 SER
+ *  11 | 74HC595 RCLK
+ *  12 | 74HC595 SCLK
+ * ----+--------------
+ *  A0 | EEPROM CE
+ *  A1 | EEPROM OE
+ *  A2 | EEPROM WE
+ * ----+--------------
+ *  13 | Activity LED
+ * ----+--------------
+ *  
+ * Copyright 2019, Erik van Zijst <[email protected]>
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ * 
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// AT28C256 contol lines
+const unsigned int EEPROM_CE = A0;
+const unsigned int EEPROM_OE = A1;
+const unsigned int EEPROM_WE = A2;
+
+// 74HC595 control lines
+const unsigned int SHIFT_SER = 10;
+const unsigned int SHIFT_RCLK = 11;
+const unsigned int SHIFT_SCLK = 12;
+
+// Activity indicator LED
+const unsigned int ACT_LED = 13;
+
+const unsigned int dataPins[] = {2, 3, 4, 5, 6, 7, 8, 9};
+
+unsigned int len;
+byte buf[4];
+
+void setup() {
+  Serial.begin(19200);
+
+  pinMode(EEPROM_CE, OUTPUT);
+  pinMode(EEPROM_OE, OUTPUT);
+  pinMode(EEPROM_WE, OUTPUT);
+
+  pinMode(SHIFT_SER, OUTPUT);
+  pinMode(SHIFT_RCLK, OUTPUT);
+  pinMode(SHIFT_SCLK, OUTPUT);
+
+  pinMode(ACT_LED, OUTPUT);
+  digitalWrite(ACT_LED, LOW);
+
+  for (unsigned int i = 0; i < 8; i++) {
+    pinMode(dataPins[i], INPUT);
+  }
+}
+
+void pulse(int pin) {
+  digitalWrite(pin, HIGH);
+  delayMicroseconds(1);
+  digitalWrite(pin, LOW);
+}
+
+/*
+ * Loads the specified 16 bit address into the 595 shift register.
+ */
+void loadShiftAddr(unsigned int addr) {
+  for (int i = 15; i >= 0; i--) {
+    digitalWrite(SHIFT_SER, ((addr >> i) & 1) ? HIGH : LOW);
+    pulse(SHIFT_SCLK);
+  }
+  pulse(SHIFT_RCLK);
+}
+
+void readAddr(unsigned int addr) {
+  loadShiftAddr(addr);
+
+  byte val = 0;
+  for (unsigned int i = 0; i < 8; i++) {
+    val |= (digitalRead(dataPins[i]) << i);
+  }
+
+  Serial.write(val);
+}
+
+void writeAddr(unsigned int addr, byte val) {
+  Serial.write(0);
+}
+
+void dump() {
+  for (unsigned int addr = 0; addr < 32768; addr++) {
+    byte val = 0;
+    loadShiftAddr(addr);
+    delayMicroseconds(1);
+    for (unsigned int i = 0; i < 8; i++) {
+      val |= (digitalRead(dataPins[i]) << i);
+    }
+    Serial.write(val);
+  }
+}
+
+void load() {
+}
+
+void loop() {
+  if (Serial.available() > 0) {
+    digitalWrite(ACT_LED, HIGH);
+
+    len = Serial.read();
+    Serial.readBytes(buf, len);
+
+    if (buf[0] == 0x72 && len == 3) {
+        readAddr((buf[1] << 8) + buf[2]);
+
+    } else if (buf[0] == 0x77 && len == 4) {
+        writeAddr((buf[1] << 8) + buf[2], buf[3]);
+
+    } else if (buf[0] == 0x64 && len == 1) {
+        dump();
+
+    } else if (buf[0] == 0x6c && len == 3) {
+        load();
+
+    } else {
+      for (int i = 0; i < 5; i++) {
+        digitalWrite(ACT_LED, LOW);
+        delay(200);
+        digitalWrite(ACT_LED, HIGH);
+        delay(200);
+      }
+    }
+    digitalWrite(ACT_LED, LOW);
+  }
+}

eeprom.py

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+#!/usr/bin/env python3
+#
+# Copyright 2019, Erik van Zijst <[email protected]>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import argparse
+import sys
+from struct import pack
+
+from serial import Serial
+from serial.tools import list_ports
+
+
+def atoi(val: str) -> int:
+    """Parses an address string into an integer.
+
+    Supports decimal, hexadecimal and octal notation.
+    """
+    return int(val,
+               16 if val.startswith('0x') else
+               8 if val.startswith('0o') else
+               10)
+
+
+def read(port: Serial, addr: str) -> None:
+    port.write(pack('>BcH', 3, b'r', atoi(addr)))
+    val = port.read(1)
+    print(int.from_bytes(val, 'big'), '/', '0x' + val.hex())
+
+
+def write(port: Serial, addr: str, val: str) -> None:
+    port.write(pack('>BcHB', 4, b'w', atoi(addr), atoi(val)))
+    print(port.read(1))
+    print('OK')
+
+
+def dump(port: Serial, filename: str) -> None:
+    with open(filename, 'wb') as f:
+        port.write(pack('>Bc', 1, b'd'))
+
+        for i in range(2**15):
+            f.write(port.read(1))
+            f.flush()
+            if i % 100 == 0:
+                print('\r%d%%' % ((i / 2**15) * 100), end='')
+    print('\nComplete.')
+
+
+def quit(*args) -> None:
+    raise EOFError()
+
+
+if __name__ == '__main__':
+    usage = """AT28C256 EEPROM Programmer
+
+Read or write individual addresses, dump out the full contents to a file, or\
+load an image file onto the ERPROM.
+
+To read a single byte:
+> [r|read] [addr]
+
+To write a byte to a specific address:
+> [w|write] [addr] [value]
+
+To dump the entire EEPROM to a file:
+> [d|dump] [filename]
+
+To load a local file into the EEPROM:
+> [l|load] [filename]
+
+Address supports hex (0xFF) and octal (0o7) notation.
+"""
+    parser = argparse.ArgumentParser(description='AT28C256 EEPROM Programmer')
+    parser.add_argument('port', nargs='?',
+                        help='the serial port the Arduino is '
+                             'connected to (on OSX typically '
+                             '/dev/tty.usbmodemXXXX)')
+    args = parser.parse_args()
+
+    dev = args.port
+    if not args.port:
+        try:
+            # attempt to autodetect the Arduino
+            dev = next(
+                filter(lambda p: p.product and 'arduino' in p.product.lower(),
+                       list_ports.comports())).device
+            print('Found Arduino at port', dev)
+        except StopIteration:
+            print('Cannot find Arduino. If it is connected, specify the port '
+                  'manually.', file=sys.stderr)
+            exit(1)
+
+    port = Serial(dev, 19200, timeout=3)
+    print(usage)
+    while True:
+        try:
+            expr = input('> ').split()
+            {'r': read,
+             'read': read,
+             'w': write,
+             'write': write,
+             'd': dump,
+             'dump': dump,
+             'quit': quit,
+             'q': quit}[expr[0]](port, *expr[1:])
+
+        except EOFError:
+            break
+        except (ValueError, KeyError, IndexError, TypeError) as e:
+            print('Invalid command:', e)

protocol.txt

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+Protocol
+
+The protocol between the Python client and Arduino is a synchronous request
+response based system. The client initiates all communication, one request
+at a time.
+
+Each request yields a response from the Arduino which must be consumed fully
+before the next request can be sent.
+
+Each request is packed into a structured binary envelope consisting of a
+leading octet indicating the length of the message (excluding the leading
+octet), followed by a single octet describing the command that is to be
+executed by the Arduino, followed by 0 up to and including 253 bytes of
+command-specific payload data:
+
+   0                   1                   2                   3
+   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |     Length    |    Command    |              Data             |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+The following commands are defined:
+
+1. Read
+
+Command byte: 'r' (0x72 / ASCII 114)
+Data: 16 bit address in network byte order. Since the AT28C256 has only 15
+address lines, only the 15 lower bits are used. The leading, MSB is unused.
+
+   0                   1                   2                   3
+   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |        3      |       'r'     |0|      15 bit address         |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+The response is a single byte containing the value at the specified address,
+without header or delimiter.
+
+2. Write
+
+Command byte: 'w' (0x77 / ASCII 119)
+Data: 3 bytes, broken down as follows: 2 bytes containing a 15 bit address
+in network byte order, followed by one octet of data to be written to the
+specified address.
+
+   0                   1                   2                   3
+   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |        4      |       'w'     |0|      15 bit address         |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |      Data     |
+  +-+-+-+-+-+-+-+-+
+
+The response is a single 0 byte to indicate the operation finished and a new
+command can be sent.
+
+3. Dump
+
+Command byte: 'd' (0x64 / ASCII 100)
+Data: No payload following the command byte.
+
+   0                   1
+   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |        0      |       'd'     |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+The response is the raw contents of the entire EEPROM. This is exactly 32KB
+of raw data without header or delimiter. The response is done after the
+32768th byte.
+
+4. Load
+
+Command byte: 'l' (0x6C / ASCII 108)
+Data: 2 bytes indicating the size of the upload that follows the request
+message. Since the AT28C256 has only 15 address lines, only the lower 15 bits
+are used. The leading, MSB is ignored.
+
+   0                   1                   2                   3
+   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+  |        3      |       'l'     |0|       15 bit length         |
+  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+
+Directly following the command message is the stream of bytes to be uploaded
+to the EEPROM. Writing always begins at address 0. The length of the stream
+must match the length advertised in the command message.
+
+The response is a single 0 byte to indicate the operation finished and a new
+command can be sent.

requirements.txt

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+pyserial==3.4