Automatic detection of 2316 chip selects

This commit is contained in:
Tom Nisbet 2024-04-09 13:02:51 -04:00
parent 073bbfd0f4
commit 08f93deee6
4 changed files with 128 additions and 16 deletions

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@ -114,6 +114,8 @@ void PromDevice::setDataBusMode(uint8_t mode)
{ {
DDRB &= 0xfc; DDRB &= 0xfc;
DDRD &= 0x03; DDRD &= 0x03;
PORTB |= 0x03; // set pullup resistors
PORTD |= 0xfc;
} }
} }

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@ -8,17 +8,25 @@
// IO lines for the EPROM device control // IO lines for the EPROM device control
// Pins D2..D9 are used for the data bus. // Pins D2..D9 are used for the data bus.
#define CS3 A0 #define CS3_PIN A0
#define CS1 A1 #define CS2_PIN A1
#define CS2 A2 #define CS1_PIN A2
#define CS3_BIT 0x04
#define CS2_BIT 0x02
#define CS1_BIT 0x01
static unsigned csBits;
// Set the status of the device control pins // Set the status of the device control pins
static void enableCS1() { digitalWrite(CS1, HIGH); } static void enableCS(unsigned pin, unsigned maskBit) { digitalWrite(pin, (csBits & maskBit) ? HIGH : LOW); }
static void disableCS1() { digitalWrite(CS1, LOW);} static void disableCS(unsigned pin, unsigned maskBit) { digitalWrite(pin, (csBits & maskBit) ? LOW : HIGH); }
static void enableCS2() { digitalWrite(CS2, HIGH); }
static void disableCS2() { digitalWrite(CS2, LOW);} static void enableCS1() { enableCS(CS1_PIN, CS1_BIT); }
static void enableCS3() { digitalWrite(CS3, HIGH); } static void disableCS1() { disableCS(CS1_PIN, CS1_BIT); }
static void disableCS3() { digitalWrite(CS3, LOW);} static void enableCS2() { enableCS(CS2_PIN, CS2_BIT); }
static void disableCS2() { disableCS(CS2_PIN, CS2_BIT); }
static void enableCS3() { enableCS(CS3_PIN, CS3_BIT); }
static void disableCS3() { disableCS(CS3_PIN, CS3_BIT); }
PromDevice23::PromDevice23(uint32_t size) PromDevice23::PromDevice23(uint32_t size)
@ -31,11 +39,12 @@ void PromDevice23::begin()
{ {
// Define the data bus as input initially so that it does not put out a // Define the data bus as input initially so that it does not put out a
// signal that could collide with output on the data pins of the EEPROM. // signal that could collide with output on the data pins of the EEPROM.
setDataBusMode(INPUT); setDataBusMode(INPUT_PULLUP);
pinMode(CS1, OUTPUT); csBits = 0; // Init to CS3, CS2, and CS1 all active LOW
pinMode(CS2, OUTPUT); pinMode(CS1_PIN, OUTPUT);
pinMode(CS3, OUTPUT); pinMode(CS2_PIN, OUTPUT);
pinMode(CS3_PIN, OUTPUT);
disableCS1(); disableCS1();
disableCS2(); disableCS2();
@ -46,9 +55,106 @@ void PromDevice23::begin()
} }
// Override the existing Unlock command to scan the different combinations of CS until
// data is found. If the CS lines are not correctly configured, the chip should not
// assert any signals on the data bus and the Arduino will read back all FF.
ERET PromDevice23::disableSoftwareWriteProtect()
{
// Finish out the Unlock message printed by the UI code
Serial.println("just kidding!");
// Scan a few different addresses in case there are legitimate empty blocks. With
// the total ROM size of 2K, it is very unlikely that there are several unused
// 16-byte blocks, so a valid set of CS pins should encounter some data.
for (uint32_t addrBase = 0x0000; (addrBase < mSize); addrBase += 0x250)
{
if (scanAddress(addrBase))
{
Serial.print("Setting CS bits to ");
printCSbits(csBits);
Serial.println();
return RET_OK;
}
}
Serial.println("No valid CS settings found");
return RET_FAIL;
}
// BEGIN PRIVATE METHODS // BEGIN PRIVATE METHODS
// //
// Print the current CS bit settings.
void PromDevice23::printCSbits(unsigned bits)
{
Serial.print("CS3:");
Serial.print((bits & CS3_BIT) ? 'H':'L');
Serial.print(" CS2:");
Serial.print((bits & CS2_BIT) ? 'H':'L');
Serial.print(" CS1:");
Serial.print((bits & CS1_BIT) ? 'H':'L');
}
// Try all combinations of the CS bits and read 16 bytes of data from the chip.
// One of the CS settings should read some non-FF data.
bool PromDevice23::scanAddress(uint32_t addrBase)
{
unsigned saveBits = 0xff;
Serial.print("\nScanning Chip Select combinations starting at address ");
printByte(addrBase >> 8);
printByte(addrBase & 0xff);
Serial.println();
for (csBits = 0; (csBits < 8); csBits++)
{
// Disable all CS bits using the new definition of csBits
disableCS3();
disableCS2();
disableCS1();
printCSbits(csBits);
Serial.print(" - ");
for (unsigned offset = 0; (offset < 16); offset++)
{
byte data = readByte(addrBase + offset);
printByte(data);
Serial.print(' ');
if (data != 0xff)
{
// this combination of Chip Selects successfully read data
saveBits = csBits;
}
}
Serial.println();
}
if (saveBits != 0xff)
{
csBits = saveBits;
return true;
}
return false;
}
static const char hex[] = "0123456789abcdef";
void PromDevice23::printByte(byte b)
{
char line[3];
line[0] = hex[b >> 4];
line[1] = hex[b & 0x0f];
line[2] = '\0';
Serial.print(line);
}
// Use the PromAddressDriver to set a 16 bit address in the two address shift registers. // Use the PromAddressDriver to set a 16 bit address in the two address shift registers.
void PromDevice23::setAddress(uint32_t address) void PromDevice23::setAddress(uint32_t address)
{ {
@ -61,7 +167,7 @@ byte PromDevice23::readByte(uint32_t address)
{ {
byte data = 0; byte data = 0;
setAddress(address); setAddress(address);
setDataBusMode(INPUT); setDataBusMode(INPUT_PULLUP);
enableCS1(); enableCS1();
enableCS2(); enableCS2();
enableCS3(); enableCS3();

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@ -24,8 +24,12 @@ class PromDevice23 : public PromDevice
PromDevice23(uint32_t size); PromDevice23(uint32_t size);
void begin(); void begin();
const char *getName() { return "23 series PROM"; } const char *getName() { return "23 series PROM"; }
ERET disableSoftwareWriteProtect(); // use the Unlock command to scan the chip selects
protected: protected:
void printCSbits(unsigned bits);
bool scanAddress(uint32_t addrBase);
void printByte(byte b);
void setAddress(uint32_t address); void setAddress(uint32_t address);
byte readByte(uint32_t address); byte readByte(uint32_t address);
bool burnByte(byte value, uint32_t address) { return false; } bool burnByte(byte value, uint32_t address) { return false; }

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@ -19,7 +19,7 @@
#include "XModem.h" #include "XModem.h"
static const char * MY_VERSION = "3.3"; static const char * MY_VERSION = "3.4";
// Global status // Global status
@ -74,7 +74,7 @@ PromDeviceSST28SF prom(512 * 1024L, 40, true);
PromDevice8755A prom(2 * 1024L); PromDevice8755A prom(2 * 1024L);
#elif defined(PROM_IS_23) #elif defined(PROM_IS_23)
PromDevice23 prom(2 * 1024L); // 2316 PromDevice23 prom(2 * 1024L); // 2316
// Additional device-specific code goes here... // Additional device-specific code goes here...
//#elif defined(PROM_IS... //#elif defined(PROM_IS...