From 4324891278fd6bfc7340def154ef174c5eca3722 Mon Sep 17 00:00:00 2001 From: Luke Kenneth Casson Leighton Date: Mon, 17 Dec 2018 14:44:02 +0000 Subject: [PATCH] add comments --- 3d_gpu/microarchitecture.mdwn | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/3d_gpu/microarchitecture.mdwn b/3d_gpu/microarchitecture.mdwn index 622a4d992..7b9d37fa5 100644 --- a/3d_gpu/microarchitecture.mdwn +++ b/3d_gpu/microarchitecture.mdwn @@ -383,6 +383,17 @@ SIMD-style (predicated) operation to take place. now that i think about it, i think we may need to have the three phases be part of a pipeline, in a single dependency matrix. +---- + +I had a state machine in one chip that could come up out of power on in a +state it could not get out of. Since this experience, I have a rule with +state machines, A state machine must be able to go from any state to idle +when the reset line is asserted. + +You have to prove that the logic can never create a circular dependency, +not a proof with test vectors, a logical proof like what we do with FP +arithmetic these days. + # Design Layout ok,so continuing some thoughts-in-order notes: @@ -606,7 +617,6 @@ costs 2 address comparators to disambiguate this short shadow in the pipeline. This is a lower expense than building another read port into the RF, in both area and power, and uses the pipeline efficiently. - # References * -- 2.30.2