et891892@levels.sait.edu.au (05/07/91)
Has anybody heard of DRAM chips / simms that have a built-in refresh counter that doesn't need to be clocked externally ? I thought I read somewhere that Samsung make chips (KM4C1002) that are pseudo static .. I would like to have a large amount of RAM ( 1MByte - 4MByte) controlled by a MC68HC11 microcontroller , but I can't work out a way of refreshing the RAM without using a complicated dedicated DRAM controller. The DRAM's do not need to be mapped into the CPU's memory map. Please reply to this newsgroup or to et891892@lux.sait.edu.au Kym Newbery -- ----------------------------------------------------------------------------- Kym B Newbery - >>MAATSUYKER<< | - MISTAKES - UNIX: et891892@lux.sait.edu.au | ' Doctors bury them......... VMS: et891892@lv.sait.edu.au | ...engineers get buried by them' ----------------------------------------------------------------------------- 3rd Year Electronic Engineering Student @ The University of South Australia -----------------------------------------------------------------------------
steveh@tasman.cc.utas.edu.au (Steven Howell) (05/09/91)
Kym, you worded my question perfectly. I also need pseudo static DRAM's After experimenting with hiddious Memory Management Units, i am convinced that large static memories or pseudo static dynamic memories will conserve the space i have avail to me. any help would be greatly appreciated. thanks in advance steve h
rupe@motcid.UUCP (Bernard Rupe) (05/10/91)
In article <steveh.673772764@tasman> steveh@tasman.cc.utas.edu.au (Steven Howell) writes: > > Kym, you worded my question perfectly. I also need pseudo static DRAM's >After experimenting with hiddious Memory Management Units, i am convinced >that large static memories or pseudo static dynamic memories will conserve >the space i have avail to me. Pseudo Static DRAMs are available from Micron Technologies. The spec I have in front of me is for a 128Kx8 PSDRAM, part number MT45C8128. Check with your local rep for more info. -- Bernie Rupe 1501 W. Shure Drive Room 1315 Motorola, Inc. Arlington Heights, IL 60004 Cellular Infrastructure Group +1 708 632 2814 rupe@green.rtsg.mot.com or ...!uunet!motcid!rupe
cjp@megatek.UUCP (Christopher J. Pikus) (05/14/91)
et891892@levels.sait.edu.au writes: > > Has anybody heard of DRAM chips / simms that have a built-in > refresh counter that doesn't need to be clocked externally ? > I thought I read somewhere that Samsung make chips (KM4C1002) > that are pseudo static .. > > ----------------------------------------------------------------------------- > Kym B Newbery - >>MAATSUYKER<< | - MISTAKES - > UNIX: et891892@lux.sait.edu.au | ' Doctors bury them......... > VMS: et891892@lv.sait.edu.au | ...engineers get buried by them' > ----------------------------------------------------------------------------- These are called pseudo-static DRAMS. They offer the density and low power consumption of DRAM with the simplicity of static RAM. They have the refresh circuitry and addressing (RAS/CAS) inside the chip. Hitachi makes them. Someone mentioned Micron too but they are US based and you might have an easier time getting Japaneese parts. -- Gun control means being able to hit your target.... Christopher J. Pikus, Megatek Corp. INTERNET: cjp@megatek.uucp San Diego, CA UUCP: uunet!megatek!cjp or ucsd!megatek!cjp