Created
April 10, 2020 15:04
-
-
Save mwkmwkmwk/bab842c996499532d4bed174a638f183 to your computer and use it in GitHub Desktop.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| dfflegalize [options] | |
| Converts all flip-flops and latches in the design to a specified subset of | |
| cells actually supported by the target device, applying conversions between | |
| cell types as necessary. | |
| -sr | |
| -dlatch | |
| -dlatchr | |
| -dlatchsr | |
| -dff | |
| -dffe | |
| -adff | |
| -adffe | |
| -dffsr | |
| -dffsre | |
| -dffs | |
| -dffse | |
| -dffes | |
| Allows the usage of the corresponding cell type in the output. | |
| If none of the above options are specified, all supported FF/latch | |
| types are assumed to be allowed. | |
| -clk-polarity <P|N> | |
| Requires that all FFs in the output have the specified clock polarity. | |
| -arst-polarity <P|N> | |
| Requires that all FFs in the output have the specified async reset polarity. | |
| -srst-polarity <P|N> | |
| Requires that all FFs in the output have the specified sync reset polarity. | |
| -lrst-polarity <P|N> | |
| Requires that all latches in the output have the specified reset polarity. | |
| -reset-polarity <P|N> | |
| Specifies all three above options at once. | |
| -len-polarity <P|N> | |
| Requires that all latches in the output have the specified enable polarity. | |
| -ce-polarity <P|N> | |
| Requires that all FFs in the output have the specified clock enable polarity. | |
| -arst-val <0|1> | |
| Requires that all FFs in the output have the given async reset value. | |
| -srst-val <0|1> | |
| Requires that all FFs in the output have the given sync reset value. | |
| -lrst-val <0|1> | |
| Requires that all latches in the output have the given reset value. | |
| -match-reset-init | |
| Requires that the initialization value matches the reset value for | |
| dlatchr, adff, adffe, dffs, dffse, dffes cells in the output. | |
| -zero-init | |
| Requires that all initialization values are 0 (or undefined) in | |
| the output. | |
| -mince <num> | |
| Requires that each clock enable signal in the output is used by | |
| at least <num> FFs. | |
| -minsrst <num> | |
| Requires that each sync reset signal in the output is used by | |
| at least <num> FFs. | |
| The following transformations are performed by this pass: | |
| - upconversion from a less capable cell to a more capable cell, if the less | |
| capable cell is not supported (eg. dff -> dffe, or adff -> dffsr) | |
| - unmapping FFs with clock enable (due to unsupported cell type or -mince) | |
| - unmapping FFs with sync reset (due to unsupported cell type, -minsrst, or | |
| -match-reset-init) | |
| - adding inverters on the control pins (due to unsupported polarity) | |
| - converting sr into dlatchr | |
| - emulating unsupported dffsr cell by adff + adff + sr + mux | |
| - emulating unsupported dlatchsr cell by dlatchr + dlatchr + sr + mux | |
| - emulating adff with -match-reset-init violation by dff + adff + dlatch + mux | |
| - emulating dlatchr with -match-reset-init violation by dlatch + dlatchr + dlatch + mux | |
| If the pass is unable to realize a given cell type (eg. adff when only -dff | |
| option is passed), an error is raised. |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment