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@ -27,19 +27,21 @@ enable and disable Software Data Protection, but uses a direct write for program
TommyPROM has a variety of PromDevice Modules that can be compiled in to support these TommyPROM has a variety of PromDevice Modules that can be compiled in to support these
different chip technologies. different chip technologies.
# Verified Chips # Verified Chips
|Model |Manufacturer |Type |Module |Notes| |Model |Manufacturer |Type |Module |Notes|
|:--- |:--- |:--- |:--- |:--- | |:--- |:--- |:--- |:--- |:--- |
|AT28C256 |Atmel, others|EEPROM |28C |Fully supported| |AT28C256 |Atmel, others|EEPROM |28C |Fully supported|
|AT28C64 |Atmel, others|EEPROM |28C |Fully supported| |AT28C64 |Atmel, others|EEPROM |28C |Fully supported|
|AT29C010 |Atmel |Flash |28C |Only with 128 byte or less sector size|
|SST39SF040|Microchip |Flash |SST39SF|All SST39SF0x0 supported| |SST39SF040|Microchip |Flash |SST39SF|All SST39SF0x0 supported|
|SST28SF040|SST |Flash |SST28SF|All SST28SF0x0 supported| |SST28SF040|SST |Flash |SST28SF|All SST28SF0x0 supported|
|SST27SF020|SST |Flash |27 |12V continuous for pgm/erase| |SST27SF020|SST |Flash |27 |12V continuous for pgm/erase|
|W27C257 |Winbond |EEPROM |27 |Continual 12V or 14V for program/erase| |W27C257 |Winbond |EEPROM |27 |Continuous 12V or 14V for program/erase|
|AT29C010 |Atmel |Flash |28C |Only with 128 byte or less sector size|
|8755A |Intel |EPROM |8755A |Requires 25V pulses to program| |8755A |Intel |EPROM |8755A |Requires 25V pulses to program|
# PromDevice Modules # PromDevice Modules
This PromDevice28C module is enabled by default to program 28C256 EEPROMS. To use a This PromDevice28C module is enabled by default to program 28C256 EEPROMS. To use a
@ -57,27 +59,15 @@ commands to enable and disable the [Software Data protection (SDP)](28C256-notes
features of 28C chips. There is also support for the fast block write mode of these features of 28C chips. There is also support for the fast block write mode of these
chips, allowing a 32KB chip to be programmed in just a few seconds. chips, allowing a 32KB chip to be programmed in just a few seconds.
## PromDevice27
The 27C EPROMs use a variety of programming algorithms. Code exists for some of these,
but very few of the chips have been tested.
Most, if not all, 27C series chips are not 5V only and require a higher voltage to program
them. Some need the voltage constantly applied while programming and others use high
voltage pulses for each byte. For constant voltage chips, it is probably easiest to just
add an external power supply and manually assert the voltage before starting a write. For
those with switched voltages, some elements of the 8755 hardware may be leveraged to build
a version of the programmer that supports these chips.
## PromDeviceSST39SF ## PromDeviceSST39SF
The SST39SF0x0 NOR Flash chips use fixed 4KB sectors that must be manually erased before a new program The SST39SF0x0 NOR Flash chips use fixed 4KB sectors that must be manually erased before a
operation, but the code manages this transparently. Whenever a write is started to a new new program operation, but the code manages this transparently. Whenever a write is
segment, the driver first initiates an erase of that sector. A second write to the same started to a new segment, the driver first initiates an erase of that sector. A second
sector will not cause an erase, so it is possible to write to a segment multiple times write to the same sector will not cause an erase, so it is possible to write to a segment
with no additional steps as long as the writes are to different parts of the sector. For multiple times with no additional steps as long as the writes are to different parts of
example, 256 bytes could be written to the start of a sector from one file and then 512 the sector. For example, 256 bytes could be written to the start of a sector from one
bytes could be written to the end of the sector from another file. file and then 512 bytes could be written to the end of the sector from another file.
Writing data that spans multiple sectors also works with no additional steps. When Writing data that spans multiple sectors also works with no additional steps. When
a sector boundary is crossed, the new sector is erased and set as the current sector. a sector boundary is crossed, the new sector is erased and set as the current sector.
@ -97,6 +87,24 @@ the 28SF are slower.
All programming and erase operations for the 28SF chips require only a single 5V power supply. All programming and erase operations for the 28SF chips require only a single 5V power supply.
## PromDevice27
The 27C supports Flash, EEPROM, and EPROM chips that use a variety of programming algorithms.
Most, if not all, 27C series chips are not 5V-only and require a higher voltage to program
or erase. This driver supports chips that need the voltage constantly applied while
programming or erasing. The programming voltages are provided by an external power supply
and manually switched before starting a write or erase operation. See the [TommyPROM32
hardware](pcb#TommyPROM32) for a diode circuit that allows the programming voltage to be
switched between Vcc and a higher voltage.
Check the [Chip Details](#27c-and-27e-series-eproms-and-flash) for the high voltage
connections for a particular chip or consult your data sheet.
Chips that use high voltage pulses for each byte are not supported. For those chips, some
elements of the [8755A hardware](8755A-hardware) may be leveraged to build a version of
the programmer that is able to provide high voltage pulses.
## PromDevice8755 ## PromDevice8755
TommyPROM has a driver for Intel 8755 EPROMs. This driver replaces the 28C driver at TommyPROM has a driver for Intel 8755 EPROMs. This driver replaces the 28C driver at
@ -117,7 +125,6 @@ need for shift registers to create address lines.
The 8755 build of TommyPROM also has a circuit to control the 25V programming pulses. The 8755 build of TommyPROM also has a circuit to control the 25V programming pulses.
# Chip Details # Chip Details
## 28C Series 28C256 ## 28C Series 28C256
@ -149,6 +156,32 @@ This is an earlier version of the SST39SF series chips. They are pin compatible
flash chips support software data protection. The _Lock_ and _Unlock_ commands can be flash chips support software data protection. The _Lock_ and _Unlock_ commands can be
used to enable and disable SDP from the command line. used to enable and disable SDP from the command line.
## 27C and 27E Series EPROMs and Flash
### W27C257 and W27C512
The Winbond W27C257 and W27E257 appear to be identical 32Kx8 EEPROMs. The 27C version
has been tested. The Winbond W27C512 is a 64Kx8 EEPROM with no dedicated _VPP_ pin.
The 257 EEPROMs have a _VPP_ pin that needs a constant 12V during programming. Unlike the
newer 28C EEPROMs, these chips do not automatically erase before writing to a location.
Instead, the entire chip is erased by applying 14V to _VPP_ and _A9_ and then pulsing
_CE_.
Unlike the 257 chips, the W27C512 does not have a dedicated pin for the programming
voltage and instead uses the OE pin to place the chip in programming mode. The verify
operation requires that the OE pin be switched to _LOW_ and there is no hardware support
for this, so the current code supports the 512 chip by doing a single write cycle with no
verify.
Because the chips use a constant high voltage for programming instead of a pulse, an
external power supply and two diodes can be used to supply either 5V or 12V to the
pins for programming and erasing.
Note that the W27x257 chip are almost a drop-in replacement for the 28C256. The _WE_,
_VPP_, and _A14_ pins are the only differences. For reading, the _VPP_ pin should be
connected to 5V.
## 29C Series ## 29C Series
The 29C0x0 chips are 5V sectored flash chips. They are similar to the 28C EEPROMs, The 29C0x0 chips are 5V sectored flash chips. They are similar to the 28C EEPROMs,
@ -187,7 +220,6 @@ data. Data is written a byte at a time using a command register to control the
programming. TommyPROM does not currently support 29F chips, but it would not be programming. TommyPROM does not currently support 29F chips, but it would not be
difficult to write a driver. The default 28C driver will read 29F chips. difficult to write a driver. The default 28C driver will read 29F chips.
## SST27SF020 ## SST27SF020
The Silicon Storage SST27SF0x0 are programmed similarly to the 27C257 in that a constant The Silicon Storage SST27SF0x0 are programmed similarly to the 27C257 in that a constant
@ -200,31 +232,6 @@ the newer 28C EEPROMs, these chips do not automatically erase before writing to
location. Instead, the entire chip is erased by applying 12V to _VPP_ and _A9_ and then location. Instead, the entire chip is erased by applying 12V to _VPP_ and _A9_ and then
pulsing _WE_. pulsing _WE_.
## 27C and 27E Series EPROMs and flash
#### W27C257 and W27C512
The Winbond W27C257 and W27E257 appear to be identical 32Kx8 EEPROMs. The 27C version
has been tested. The Winbond W27C512 is a 64Kx8 EEPROM with no dedicated _VPP_ pin.
The 257 EEPROMs have a _VPP_ pin that needs a constant 12V during programming. Unlike the
newer 28C EEPROMs, these chips do not automatically erase before writing to a location.
Instead, the entire chip is erased by applying 14V to _VPP_ and _A9_ and then pulsing
_CE_.
Unlike the 257 chips, the W27C512 does not have a dedicated pin for the programming
voltage and instead uses the OE pin to place the chip in programming mode. The verify
operation requires that the OE pin be switched to _LOW_ and there is no hardware support
for this, so the current code supports the 512 chip by doing a single write cycle with no
verify.
Because the chips use a constant high voltage for programming instead of a pulse, an
external power supply and two diodes can be used to supply either 5V or 12V to the
pins for programming and erasing.
Note that the W27x257 chip are almost a drop-in replacement for the 28C256. The _WE_,
_VPP_, and _A14_ pins are the only differences. For reading, the _VPP_ pin should be
connected to 5V.
# Chips to be Tested # Chips to be Tested
@ -234,7 +241,8 @@ connected to 5V.
|W27C512 |Winbond |EEPROM |27 |Continual 12V or 14V for program/erase,VPP on OE| |W27C512 |Winbond |EEPROM |27 |Continual 12V or 14V for program/erase,VPP on OE|
|AM28F512 |AMD |EEPROM | || |AM28F512 |AMD |EEPROM | ||
|AM29F040 |AMD |EEPROM | || |AM29F040 |AMD |EEPROM | ||
|AMS29AF010| | | || |AMS29AF010|AMS | | ||
# Chip Manufacturers # Chip Manufacturers