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Thanks for your response Galen, The problem with the 68EZ328 that I am using is that is has upper and lower write enable signals (UWE* LWE*) and not upper and lower chip enable signals. It has a single output enable (OE*) for read operations as it always expects 16 bits to be supplied. The core then looks at either the upper or lower 8 bits if only an 8 bit read was required. The 16 bit SRAMs I have seen require upper and lower byte (UB & LB) enables (ie both read and write). So for read operations the OE* signal from processor needs to connect to both UB and LB of SRAM and for write operations the UWE* and LWE* signals need to connect to the UB and LB of SRAM. This requires some glue logic. If your are really interested there is an app note on motorola web site for 68EZ328 (see http://www.mot.com/SPS/WIRELESS/pdf/APPNOTES/sram_16bit.pdf) TIA David Williams ---------- From: Galen Seitz[SMTP:galens@northwest.com] Sent: Wednesday, August 18, 1999 11:02 AM To: davidwilliams@ozemail.com.au Subject: Re: 16 bit RAM on 68K system. What ram were you planning to use? I just looked at a samsung databook and their 64Kx16 SRAM has /CS, /UB, and /LB. This ought to work with the 328 without any glue logic. The part number is KM616V1000B. I'm not necessarily advocating Samsung. I think you should be able to find several vendors who make suitable parts. Cypress, Toshiba, Hitachi, and SMOS come to mind. hope this helps, galen -- Galen Seitz galens@alum.mit.edu hm 503-525-7949 wk 503-617-0808 x109 wk fax 503-617-0809 ------ Want more information? See the CrossGCC FAQ, http://www.objsw.com/CrossGCC/ Want to unsubscribe? Send a note to crossgcc-unsubscribe@sourceware.cygnus.com
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