diff --git a/docs/_docs/design-250-prom-specific-code.md b/docs/_docs/design-250-prom-specific-code.md index fe1237f..db36d36 100644 --- a/docs/_docs/design-250-prom-specific-code.md +++ b/docs/_docs/design-250-prom-specific-code.md @@ -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 different chip technologies. + # Verified Chips |Model |Manufacturer |Type |Module |Notes| |:--- |:--- |:--- |:--- |:--- | |AT28C256 |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| |SST28SF040|SST |Flash |SST28SF|All SST28SF0x0 supported| |SST27SF020|SST |Flash |27 |12V continuous for pgm/erase| -|W27C257 |Winbond |EEPROM |27 |Continual 12V or 14V for program/erase| -|AT29C010 |Atmel |Flash |28C |Only with 128 byte or less sector size| +|W27C257 |Winbond |EEPROM |27 |Continuous 12V or 14V for program/erase| |8755A |Intel |EPROM |8755A |Requires 25V pulses to program| + # PromDevice Modules 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 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 -The SST39SF0x0 NOR Flash chips use fixed 4KB sectors that must be manually erased before a new program -operation, but the code manages this transparently. Whenever a write is started to a new -segment, the driver first initiates an erase of that sector. A second write to the same -sector will not cause an erase, so it is possible to write to a segment multiple times -with no additional steps as long as the writes are to different parts of the sector. For -example, 256 bytes could be written to the start of a sector from one file and then 512 -bytes could be written to the end of the sector from another file. +The SST39SF0x0 NOR Flash chips use fixed 4KB sectors that must be manually erased before a +new program operation, but the code manages this transparently. Whenever a write is +started to a new segment, the driver first initiates an erase of that sector. A second +write to the same sector will not cause an erase, so it is possible to write to a segment +multiple times with no additional steps as long as the writes are to different parts of +the sector. For example, 256 bytes could be written to the start of a sector from one +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 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. +## 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 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. - # Chip Details ## 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 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 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 difficult to write a driver. The default 28C driver will read 29F chips. - ## SST27SF020 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 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 @@ -234,12 +241,13 @@ connected to 5V. |W27C512 |Winbond |EEPROM |27 |Continual 12V or 14V for program/erase,VPP on OE| |AM28F512 |AMD |EEPROM | || |AM29F040 |AMD |EEPROM | || -|AMS29AF010| | | || +|AMS29AF010|AMS | | || + # Chip Manufacturers |Name |Code |Notes| -|:--- |:--- |:--- | +|:--- |:---|:---| |AMS - Advanced Memory Systems|AMS |Merged with Intersil| |AMD - Advanced Micro Devices |AM || |Atmel |AT |Aquired by Microchip|