Post by thread:Serial Ram Chips?

Hi, Does anyone know if there are any large (> 2KBytes) ram chips that are serial addressable. I've seen that there are quite a few EERAM chips, and quite a few 256 Byte chips. I have a data logging application that needs 8KB -32 KB of RAM. Thanks, Peter. -- _______________________________________________________________________ Peter Homann email: spam_OUTpeterhTakeThisOuTadacel.com.au Work : +61 3 9596-2991 Adacel Pty Ltd Fax : +61 3 9596-2960 250 Bay St, Brighton 3186, VIC, AUSTRALIA Mobile : 014 025-925

>EERAM chips, and quite a few 256 Byte chips. > >I have a data logging application that needs 8KB -32 KB of RAM. Dallas Semiconductor, of course, makes loads of NV-SRAM but mostly parallel. They also have the support chips which turn regular SRAMs into NVs by inserting them in the Vcc pins. They have a serial 16-pin NV-Ram called "EconoRAM". They have NV-RAMs that are SIPs and stand up on end (if that helps). XICOR makes a much smaller EEPROM which *also* has a shadow RAM feature (you write to the SRAM and it automatically transfers it to EEPROM on power down). Phillips makes, for example, 256B I2C device PCF8570.. BENCHMARQ is another NV-RAM vendor. I'd like to hear what you end of with. .....Thomas.CoonanKILLspam@spam@Sciatl.com

>Hi, > >Does anyone know if there are any large (> 2KBytes) ram chips that >are serial addressable. I've seen that there are quite a few >EERAM chips, and quite a few 256 Byte chips. > >I have a data logging application that needs 8KB -32 KB of RAM. > >Thanks, > >Peter. >-- >_______________________________________________________________________ >Peter Homann email: peterhKILLspamadacel.com.au Work : +61 3 9596-2991 >Adacel Pty Ltd Fax : +61 3 9596-2960 >250 Bay St, Brighton 3186, VIC, AUSTRALIA Mobile : 014 025-925 Two companies who are currently advertising this kind of device: EXEL at http://www.exel.com XICOR at http://www.xicor.com Reg .....................Reg Neale..................... "Ignorance is a renewable resource" P.J. O'Rourke

>Hi, > >Does anyone know if there are any large (> 2KBytes) ram chips that >are serial addressable. I've seen that there are quite a few >EERAM chips, and quite a few 256 Byte chips. > >I have a data logging application that needs 8KB -32 KB of RAM. > >Thanks, > >Peter. Digi-Key (http://www.digikey.com) sells microchip and national serial eeproms upto 16K bits (2K bytes). These devices are listed in the manufactures data books as upto 64K bit versions. Upto 8 devices can be daisy chained on the same I/O. Best of all they are 8 pin dip or surface mount. download data specs from microchip. michael

-- [ From: Peter L. Taylor * EMC.Ver #2.5.02 ] -- > >Does anyone know if there are any large (> 2KBytes) ram chips that > >are serial addressable. I've seen that there are quite a few > >EERAM chips, and quite a few 256 Byte chips. > > > >I have a data logging application that needs 8KB -32 KB of RAM. > > > >Thanks, > > > >Peter. > > Digi-Key (http://www.digikey.com) sells microchip and national serial eeproms upto 16K > bits (2K bytes). These devices are listed in the manufactures data books as > upto 64K bit versions. Upto 8 devices can be daisy chained on the same I/O. > Best of all they are 8 pin dip or surface mount. > > download data specs from microchip. > > michael > National Semiconductor makes a 4M/8M bit serial flash ram part. The part numbers are: NM29A040/080. The data sheet is one their web page (www .natsemi.com/), or I could e-mail it to anyone interested. The parts come in a 28 pin SOIC or PLCC. Only 6 pins are used; the die must be really big . The only gotchas of this part are: 1)It is National Microwire compatible, which isn't necessarily Microchip SPI compatible, 2)Before using the part you have to read the upper block to find any bad blocks that shouldn't be used. If anyone figures out how to use the Microchip SSP port, in SPI mode, with this part, please let me know. As far as I can figure, the only way to interface to it is use three port lines, and bypass the SSP module. Peter Taylor TransEra Corp.

Peter Homann wrote: > I have a data logging application that needs 8KB -32 KB of RAM. > Peter, Parallax has an app note that interfaces a PIC16C55 to a 1Mb X 1 Dynamic Ram chip. You can get this app note (and all of the rest of their app notes) via ftp: ftp://ftp.parallaxinc.com/pub/acrobat/picapps.pdf Their home page is at http://www.parallaxinc.com/ This approach certainly meets your 32K X 8 = 256k bit memory requirements. However, it sucks up 15 I/O pins in the process. (Actually, you could get by with using only 12 in your application.) This is more than a serial interface, but less than a standard parallel interface. Scott