diff options
author | Eddie Hung <eddie@fpgeh.com> | 2019-10-04 22:24:15 -0700 |
---|---|---|
committer | Eddie Hung <eddie@fpgeh.com> | 2019-10-04 22:31:04 -0700 |
commit | 12fd2ec4f05ce5efda2a2d2e4d37aef013f2baf9 (patch) | |
tree | 8e8058f740e9e0233065ae41a6285e1ed537430a /passes/pmgen | |
parent | 14e4aeece6adc0808ab1876f01752acb0833185a (diff) | |
download | yosys-12fd2ec4f05ce5efda2a2d2e4d37aef013f2baf9.tar.gz yosys-12fd2ec4f05ce5efda2a2d2e4d37aef013f2baf9.tar.bz2 yosys-12fd2ec4f05ce5efda2a2d2e4d37aef013f2baf9.zip |
Improve comments for xilinx_dsp_CREG
Diffstat (limited to 'passes/pmgen')
-rw-r--r-- | passes/pmgen/xilinx_dsp_CREG.pmg | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/passes/pmgen/xilinx_dsp_CREG.pmg b/passes/pmgen/xilinx_dsp_CREG.pmg index 3d911b478..3f8486406 100644 --- a/passes/pmgen/xilinx_dsp_CREG.pmg +++ b/passes/pmgen/xilinx_dsp_CREG.pmg @@ -7,11 +7,12 @@ // (attached to at most two $mux cells that implement clock-enable or // reset functionality, using a subpattern discussed below) // Notes: -// - Separating out CREG packing is necessary since there is no guarantee -// that the cell ordering corresponds to the "expected" case (i.e. the order -// in which they appear in the source) thus the possiblity existed that a -// register got packed as a CREG into a downstream DSP that should have -// otherwise been a PREG of an upstream DSP that had not been visited yet +// - Running CREG packing after xilinx_dsp_pack is necessary since there is no +// guarantee that the cell ordering corresponds to the "expected" case (i.e. +// the order in which they appear in the source) thus the possiblity existed +// that a register got packed as a CREG into a downstream DSP that should +// have otherwise been a PREG of an upstream DSP that had not been visited +// yet // - The reason this is separated out from the xilinx_dsp.pmg file is // for efficiency --- each *.pmg file creates a class of the same basename, // which when constructed, creates a custom database tailored to the @@ -28,7 +29,7 @@ state <SigSpec> sigC sigP state <bool> ffCcepol ffCrstpol state <Cell*> ffC ffCcemux ffCrstmux -// subpattern +// Variables used for subpatterns state <SigSpec> argQ argD state <bool> ffcepol ffrstpol state <int> ffoffset |