Post by thread:How to connect PIC to DRAM (esp. SIMM)

Hey. >In my current project I have to strore a big amount of information (about > 256-512K). I'm waiting for any ideas. I interfaced a 16c74 to a 256k 30 pin simm. Nothing really tricky about it. Used a timer interrupt to generate refresh cycles, and a bunch of I/O pins to drive the busses and control signals. I downloaded the datasheets for the dram chips on the simm to get the timing right. I think the Fujitsu docs had a pretty good description. later, newell

At 01:52 AM 10/6/97 +0200, you wrote: >>> In my current project I have to strore a big amount of information (about >>> 256-512K). I'm waiting for any ideas. > >> Flash. > >I'm more programmer, so please recommend me one. the Am29F400AT from AMD might be a good choice. it's a 512K by 8 bit part, 5V-only operation. AMD has parts all the way up to 2 meg by 8 bit. -bill von

>>> In my current project I have to strore a big amount of information >>> (about 256-512K). I'm waiting for any ideas. > >> Flash. > >I'm more programmer, so please recommend me one. Atmel has flash with a serial interface ("Serial dataflash".) I think it comes in 2, 4, and 8 Mbit (256k, 512k 1M.) See their website. BillW

On Mon, 6 Oct 1997, Evgeni Nikolov wrote: > Hi All, > > In my current project I have to strore a big amount of information (about > 256-512K). I'm waiting for any ideas. > PTM: DRAM needs power. It is not a very good selection in a small power system. Use SRAM instead It costs more and needs bigger box, but it is much more simple and runs out of a small battery for hours or even days. If it shoud run for weeks, use FLASH. If you use mains voltage, I'll recommend a PC. Old PC's are lying there around for nothing. We have used them because the programs can be written much more freely. Data I/O can be made either thru LPT or RS232-port or a 8255-card. You can not beat the price of an old 4.77 PC ;) -------------------------------------------------------------------------- PTM, spam_OUTpasi.mustalahtiTakeThisOuTutu.fi, .....ptmustaKILLspam@spam@utu.fi, http://www.utu.fi/~ptmusta Lab.ins. (mikrotuki) ATK-keskus/Mat.Luon.Tdk OH1HEK Lab.engineer (PC support) Computer Center OI7234 Mail: Turun Yliopisto / Fysla, Vesilinnantie 5, 20014 Pt 02-3336669, FAX 02-3335632 (Pk 02-2387010, NMT 049-555577) --------------------------------------------------------------------------

part 0 585 bytes > try the Nexcom NX25F080AT-16C5-R1 Serial Flash. > Nexcom is at SunnyVale, CA (408 730 3690) > You'll need a minimum of ports - serial flash is easy I want thank All of you for your suggestions about storing a big amount of information. Someone suggested to use a XT's mainboard - well, it is acceptable, but I have space limitations - the device should be as smaller as it is possible. I have another question - can you tell me what are the prices of these FLASH roms - about 512k - 1M in your countries. I would like to compare them with these in Bulgaria. Evgeni

Evgeni Nikolov wrote: > > Hi All, > > > try the Nexcom NX25F080AT-16C5-R1 Serial Flash. > > Nexcom is at SunnyVale, CA (408 730 3690) > > > You'll need a minimum of ports - serial flash is easy > > I want thank All of you for your suggestions about storing a big amount of information. Someone suggested to use a XT's mainboard - well, it is acceptable, but I have space limitations - the device should be as smaller as it is possible. > > I have another question - can you tell me what are the prices of these FLASH roms - about 512k - 1M in your countries. I would like to compare them with these in Bulgaria. > > Evgeni > > --------------------------------------------------------------- > > Part 1.2 Type: application/ms-tnef > Encoding: base64 Hi, Evgeni! Stiga si se ebaval s ceni na Flash pameti w Balgaria i w drugite strani i drugi takiwa gluposti. Polzvaj saveta na onzi pitch, deto ti predlaga da opravisch neststa s 30 pin RAM modul ot star komputar-taka ste ti izleze naj evtino i barzo. ( By the way, kade si vizdal ti vaobste Flash memories v Balgaria, tsche i cenite im da sravnjavasch?

part 0 1563 bytes > Hi, Evgeni! > Stiga si se ebaval s ceni na Flash pameti w Balgaria i w drugite strani > i drugi takiwa gluposti. Polzvaj saveta na onzi pitch, deto ti predlaga > da opravisch neststa s 30 pin RAM modul ot star komputar-taka ste ti > izleze naj evtino i barzo. ( By the way, kade si vizdal ti vaobste Flash > memories v Balgaria, tsche i cenite im da sravnjavasch? Since I thing that all other guyes don't understand bulgarian language, I want to excuse myself that I'll answer both in English and Bulgarian. So the question from Emil was if I ever saw FLASH memories in Bulgaria. Well, in Sofia there is a company - Comet electronics. They made me an offer to deliver any component that I need if it is presented in Farnell's catalogue. And also next months I'll travel a lot along Europe (electronics is my hobby - I work in Deloytte & Touche as a programmer and IT consultant), so I hope I'll be able to purchase FLASH memories >from Germany or England. Shto da se ebavam be. Ne znam dali jiveesh v Sofia, ama tuka az se seshtam za pone dve firmi deto sa saglasni i lunen prah da mi dostaviat ako si platia. S DHL ne e chak tolkoz skupo. Kolkoto do PC-to - ne stava. Ustroistvoto deto go pravia, triabva da ne e po-goliamo ot kibritena kutiia. E, viarno che moia PSION e s takiva razmeri i otgovaria na vsichki iziskvania (i FLASH memory si ima, i RS232 si ima, che i 200 USD struva), ama ne za tova govoria. Na vuprosa dali sum vijdal FLASH memories v Bulgaria - da, v moia kompiutur BIOS-a e na FLASH:-) Evgeni