Jerry's answer is correct. Microchip does not know the timing because the 17LC44 has not been characterized for low voltage operation of the external memory bus. We currently have no plans to complete this characterization. You can certainly expect derating of the 4.5-6.0V timing specifications when operating at the lower voltage, particularly if there is a large capacitive load on the bus. Rgds, Brian. bboles@microchip.com ______________________________ Reply Separator _________________________________ Subject: PIC17LC4X Question Author: Jerry English at Internet_Exchange Date: 10/18/96 10:09 AM Joshua Woods wrote --Hi, -- I want to use a 17LC44 in a low power design running in expanded -- microcontroller mode. However, on P190 ish of the latest data sheet --- it has Memory interface timing, which says "NOT SUPPORTED IN THE PIC17LC4X DEVICES." --Q: Does this mean an LC part canot access external memory interface? --Thanks.. --Joshua Woods --j.woods@qut.edu.au --http://www.scsn.bee.qut.edu.au ----- End Included Message ----- Joshua, an excellant question. I asked the same question about three weeks ago. The quick answer was "well, it does access external memory, but we really don't know the timing at the lower voltages so thats why the note not supported." So I asked what is the timing? And I am still waiting for the answer. If Microchip tells you please post the answer so we all will know. Jerry