Add assertion on CEASE line

[mwachs5]

Related issue:
Follow-up to #2419

Type of change: other enhancement

Impact: API addition (no impact on existing code)

Development Phase: implementation

Release Notes

Add an assertion that CEASE will not go low once raised until after reset

[hcook]

LGTM as a notional follow-up to #2419, but this isn't rebased on that and FYI they touch literally the same lines of code

[mwachs5]

oh i thought #2419 was already merged, my bad

[aswaterman]

Thanks @mwachs5, #2419 is merged now, so you can rebase

[aswaterman]

chisel assertions indeed are disabled during reset - it’s literally implemented as assert(reset || cond), IIRC

…

On Sat, Apr 25, 2020 at 4:49 PM Megan Wachs ***@***.***> wrote: ***@***.**** commented on this pull request. ------------------------------ In src/main/scala/tile/Interrupts.scala <#2420 (comment)> : > @@ -102,7 +102,13 @@ trait SourcesExternalNotifications { this: BaseTile => saturated } val (cease, _) = ceaseNode.out(0) - cease(0) := could_cease.map(waitForQuiescence(_)).getOrElse(false.B) + cease(0) := could_cease.map{ c => + val cease = (waitForQuiescence(c)) + // Test-Only Code -- + val prev_cease = RegNext(c, false.B) + assert((!(prev_cease & !c) | reset.asBool), "CEASE line can not glitch once raised") ⬇️ Suggested change - assert((!(prev_cease & !c) | reset.asBool), "CEASE line can not glitch once raised") + assert(!(prev_cease & !c), "CEASE line can not glitch once raised") I *think* assertions are already disabled during reset? @jchang0 <https://github.com/jchang0> ? — You are receiving this because your review was requested. Reply to this email directly, view it on GitHub <#2420 (review)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAH3XQSDPU2OYLLA5JZQ3LLRONZG5ANCNFSM4MK4MGUQ> .

[mwachs5]

@jchang0 can I get a review on this?