On 21/08/13 10:35, John Klos wrote:
Hi,I'm curious about the CVAX SOC in the VAXstation VLC. According to Bob Supnik's site here:http://simh.trailing-edge.com/semi/cvax.htmlthe CVAX SOC is basically a shrunk 78034, CFPA and 8KB of cache on a single die. However, the dmesg from my VLC says it has 6KB of cache:cpu0 at mainbus0: KA48, SOC, 6KB L1 cacheJust curious - which is correct? Also, Bob's site says it's L2 cache but NetBSD's dmesg calls it L1. Is the KA48 a newer version of the SOC?
EK-V48B-SV.001 claims that SOC had an 8KB cache. (Well, my notes claim that that manual makes the claim - I don't have it to hand right now).
I think there was only one SOC. However, I do know that DECnis had no use for the FPU (for example) and only needed some of the cache lines to work (my possibly faulty memory suggests 6 of 8 or thereabouts). That way the DECnis group could use chips that would otherwise have been factory floor scrapins (or keyrings ...) and so could get them at a discount. Other groups building embedded systems may have done similar things.
Antonio