info-vlsi@ucbvax.ARPA (03/10/85)
From: <unido!mcvax!cernvax!harald@BERKELEY> We have been participants on an MPC. The technology is 5 micron CMOS (AMI). On testing we find that all outputs show levels in the range of 2-3 Volts, using a supply of 5 Volts. We have measured both pull-up and pull-down transistors in the pad driver to be ON. This also explains the rather high power consumption. Now, other chips on the MPC have had working pad-drivers so we must conclude processing has been O.K. Can anyone explain how both pull-up and pull-down transistors can be switched on? And also what we should look for when we get access to a probe- station? I must also mention that we have used the 5 micron standard cell library from AMI. Please answer directly to me, as I have not received any mail yet from the INFO-VLSI mailing list. Best Regards, Harald Haugan Harald Haugan Usenet: ucbvax!decvax!mcvax!cernvax!harald CERN, Division DD ARPA: no direct connection, but 1211 Geneve 23 bassen@oslo-vax will eventually get here. Switzerland
info-vlsi@ucbvax.ARPA (03/13/85)
From: stephany.WBST@XEROX.ARPA Harald: This is a guess. It may be that the chip has too much illumination. All Silicon transitors are photosensitive. we had this problem with a MPC chip two years ago: a shift register did not work properly until a piece of black tape was placed over the chip stopping the light. Hope this might help you. Joe