Looking for PLD with embedded memory

Started by Philipp Klaus Krause July 31, 2007
I'm looking a PLD with 5V TTL-compatible I/O that has ~2Mb of integrated
memory that can be used as ROM and ~64Kb of integrated memory that can
be used as EEPROM.

Initially I considered using a parallel EPROM, serial EEPROM together
with lots of TTL, but soon I realized that the EPROM, EEPROM together
with a 22V10 GAL and a 74573 register would be a simpler solution.
A few days ago I noticed how cheap CPLDs are today and that one,
together with a 3.3V voltage regulator could replace the GAL and register.

Now I ask myself if there is some PLD that could replace the EEPROM or
EPROM, too.

Philipp
Philipp Klaus Krause schrieb:
> I'm looking a PLD with 5V TTL-compatible I/O that has ~2Mb of integrated > memory that can be used as ROM and ~64Kb of integrated memory that can > be used as EEPROM. > > Initially I considered using a parallel EPROM, serial EEPROM together > with lots of TTL, but soon I realized that the EPROM, EEPROM together > with a 22V10 GAL and a 74573 register would be a simpler solution. > A few days ago I noticed how cheap CPLDs are today and that one, > together with a 3.3V voltage regulator could replace the GAL and register. > > Now I ask myself if there is some PLD that could replace the EEPROM or > EPROM, too. > > Philipp
The device doesn't have to be fast, 8 Mhz for a simple design would be OK. I need about 40 I/O. Philipp
> The device doesn't have to be fast, 8 Mhz for a simple design would be > OK. I need about 40 I/O.
You probably won't find such a PLD. Maybe you can implement your solution in software. 8 MHz is quite slow and there are lots of microcontrollers with integrated memory for you to look at. Regards, Marc
Philipp Klaus Krause <pkk@spth.de> writes:

> I'm looking a PLD with 5V TTL-compatible I/O that has ~2Mb of integrated > memory that can be used as ROM and ~64Kb of integrated memory that can > be used as EEPROM.
The Altera Max-II has 8Kb FLASH memory if that can be of any help: http://altera.com/products/devices/cpld/max2/features/flash/mx2-flash_memory.html Petter -- A: Because it messes up the order in which people normally read text. Q: Why is top-posting such a bad thing? A: Top-posting. Q: What is the most annoying thing on usenet and in e-mail?
On 31 Jul., 11:19, Philipp Klaus Krause <p...@spth.de> wrote:
> Philipp Klaus Krause schrieb: > > > I'm looking a PLD with 5V TTL-compatible I/O that has ~2Mb of integrated > > memory that can be used as ROM and ~64Kb of integrated memory that can > > be used as EEPROM. > > > Initially I considered using a parallel EPROM, serial EEPROM together > > with lots of TTL, but soon I realized that the EPROM, EEPROM together > > with a 22V10 GAL and a 74573 register would be a simpler solution. > > A few days ago I noticed how cheap CPLDs are today and that one, > > together with a 3.3V voltage regulator could replace the GAL and register. > > > Now I ask myself if there is some PLD that could replace the EEPROM or > > EPROM, too. > > > Philipp > > The device doesn't have to be fast, 8 Mhz for a simple design would be > OK. I need about 40 I/O. > > Philipp
the only devices with onchip user flash are Actel Fusion and Lattice XP2 but they are not 5V tolerant. there is and will not be any single chip solution that is 5V tolerant meets your needs. hm, ST has some products based on waferscale stuff, they all include some flash and smallish PLD, but I guess they will not directly match your needs either Antti
Antti schrieb:

> hm, ST has some products based on waferscale stuff, they all include > some flash and smallish PLD, but I guess they will not directly match > your needs either
ST's PSD would do feature-wise, but they seem to be rather expensive. The cheapest I found at digikey is at ~7&euro;, current solution would be ~3&euro; (XC9536XL: 0.8 &euro;, 2Mb EPROM: 1&euro;, voltage regulator: 0.6&euro;, EEPROM: 0.3&euro;) (all proces per piece when ordering 100). Philipp
Philipp Klaus Krause wrote:

> Philipp Klaus Krause schrieb: > >>I'm looking a PLD with 5V TTL-compatible I/O that has ~2Mb of integrated >>memory that can be used as ROM and ~64Kb of integrated memory that can >>be used as EEPROM. >> >>Initially I considered using a parallel EPROM, serial EEPROM together >>with lots of TTL, but soon I realized that the EPROM, EEPROM together >>with a 22V10 GAL and a 74573 register would be a simpler solution. >>A few days ago I noticed how cheap CPLDs are today and that one, >>together with a 3.3V voltage regulator could replace the GAL and register.
Correct. 22V10 + '573 => 32 macrocell CPLD.
>> >>Now I ask myself if there is some PLD that could replace the EEPROM or >>EPROM, too.
Yes, but not to 2Mb of memory.
> The device doesn't have to be fast, 8 Mhz for a simple design would be > OK. I need about 40 I/O.
What does this connect to ? - ie where does this ROM code go ? Is there a processor in the system, reading this, or something else ? -jg
Jim Granville schrieb:
>> The device doesn't have to be fast, 8 Mhz for a simple design would be >> OK. I need about 40 I/O. > > What does this connect to ? - ie where does this ROM code go ? > Is there a processor in the system, reading this, or something else ?
It goes into a Z80-based system from the 80s. The system has a cartridge port, where D0...D7 (data), A0...A14 (addres bus, A15 missing), E8...EE (chip enable). Back in the 80s a cartridge would contain one to four 64 KBit EPROMS containing a program. Each enable line would be used as a chip enable. I've written a few programs for the system. So far each did fit into 32KB, so I used a 256 KBit EPROM together with a 74LS21 (to connect the four chip enable lines to the EPROM's output and chip enable) for my cartridges. Now I'd like to write a program that uses more ROM and I'd like to be able to save some data. I think dividing the address space into lower 24KB (directly mapped as before) middle 4KB (bank-switched), upper 4KB (to locate some control registers to switch the middle 4KB and control the I&#2013266098;C line to the EEPROM) would make sense. Philipp
Philipp Klaus Krause <pkk@spth.de> writes:
> I'm looking a PLD with 5V TTL-compatible I/O that has ~2Mb of integrated > memory that can be used as ROM and ~64Kb of integrated memory that can > be used as EEPROM.
You're going to be looking for a long time. You can get that much RAM, but not in a part with 5V tolerant I/O. You can get built-in flash memory, but not EEPROM. I suspect that you just need to use a 3.3V part with appropriate level shifters or QuickSwitch parts (or equivalent) to get your 5V tolerance (or possibly just series resistors), and a separate EEPROM chip.
Philipp Klaus Krause wrote:
> Jim Granville schrieb: > >>>The device doesn't have to be fast, 8 Mhz for a simple design would be >>>OK. I need about 40 I/O. >> >>What does this connect to ? - ie where does this ROM code go ? >>Is there a processor in the system, reading this, or something else ? > > > It goes into a Z80-based system from the 80s. The system has a cartridge > port, where D0...D7 (data), A0...A14 (addres bus, A15 missing), E8...EE > (chip enable). Back in the 80s a cartridge would contain one to four 64 > KBit EPROMS containing a program. Each enable line would be used as a > chip enable. > I've written a few programs for the system. So far each did fit into > 32KB, so I used a 256 KBit EPROM together with a 74LS21 (to connect the > four chip enable lines to the EPROM's output and chip enable) for my > cartridges. > Now I'd like to write a program that uses more ROM and I'd like to be > able to save some data. I think dividing the address space into lower > 24KB (directly mapped as before) middle 4KB (bank-switched), upper 4KB > (to locate some control registers to switch the middle 4KB and control > the I&#2013266098;C line to the EEPROM) would make sense.
Have you looked at FLASH rather than EPROM ? Then you might be able to dispense with the EEPROM. If you use a small CPLD (XC9536, or ATF1502ASL ) you will be able to do all the chip select/banking/mapping you need, as well as get a phantom write path for the Flash. -jg