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base repository: GlasgowEmbedded/glasgow
base: b82a151facf1
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head repository: GlasgowEmbedded/glasgow
compare: 468e706f4eb7
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  • 2 commits
  • 1 file changed
  • 1 contributor

Commits on Apr 7, 2019

  1. gateware.fx2_crossbar: re-register FX2 outputs. 

    Before this commit, the FX2 arbiter would incorrectly use FX2 outputs
in the fabric that were actually only valid for 1/2 of IFCLK period,
because they were DDR input signals. After this commit, these signals
are correctly re-registered in fabric so that they are valid for
an entire IFCLK period, increasing latency by one cycle.

At last, this can be done safely, by extending the pipeline logic by
one more stage. This adds a wait state, but we can fix that later.

This improves Fmax by a factor of 1.5-1.8.

Fixes #89 (again).
    @whitequark
    whitequark committed Apr 7, 2019
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  2. gateware.fx2_crossbar: eliminate wait states. 

    Instead of wait states, pipelining logic is extended to invalidate
flags while an operation is in progress.
    @whitequark
    whitequark committed Apr 7, 2019
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    468e706 View commit details
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