Newer versions of sv2v carry through elaboration system tasks like
$fatal. ibex_top_tracing uses $fatal, but isn't actually used in the
syn_yosys flow. By using -defer, unused modules like ibex_top_tracing
are not elaborated in Yosys.
1. Missing prim_assert in ibex_top.sv (more of an rtl bug but only found
in running synthesis scripts)
2. Write out the pre-mapped netlist before mapping latches
Relates to #1335
Signed-off-by: Tom Roberts <tomroberts@lowrisc.org>
This commit creates a new top level wrapping the core, register file and
icache RAMs. The tracing top level is also renamed to ibex_top_tracing
to match. This new top level is intended to enable a dual core lockstep
implementation of Ibex.
There are no functional changes in this commit, only wiring.
Signed-off-by: Tom Roberts <tomroberts@lowrisc.org>
This fixes a bug where .csv.rpt files weren't being generated properly.
OpenSTA was outputting a simple 'Q' or 'D' for start and end path points
where the full instance name was required (which is then fed to yosys to
translate to a human readable name). The issue was in the `timing_report`
proc in syn/tcl/sta_utils.tcl which needed to request the full name of
the start and end points.
The syn README is updated to note which tool versions have been used to
test the flow.
Fixes#1193
This commit replaces the previous combination of `RV32M` bit parameter
used to en/disable the M extension and the `MultiplierImplementation`
used to select the multiplier implementation by a single enum parameter.
Signed-off-by: Pirmin Vogel <vogelpi@lowrisc.org>
- Add a technology map for latches (only works with nandgate45 library
at the moment)
- Add a real latch-based clock gating cell
- Update timing path reporting to differentiate between register and
latch paths
- Update summary results in README to reflect the latch-based numbers,
plus add numbers for a micro-riscy-style (RV32EC) config
Signed-off-by: Tom Roberts <tomroberts@lowrisc.org>
Correcting some small issues that cause newer versions of OpenSTA to
fail (previously it issued an error and continued).
- ABC/OpenSTA disagree how set_driving_cell command works so introduce
seperate ABC SDC file
- Run clean before generating STA netlist, otherwise yosys generates
some assignements to unused wires that OpenSTA's verilog parser dislikes
Adds an 'uprate' clock period which is subtracted off the desired period
and given to ABC as the target clock period. This gives better overal
timing results with minimal area impact.
Adds significant functionality to synthesis flow. Timing reports are
generated using OpenSTA and an area report is generated. Flow supports
open Nangate45 library from OpenROAD.
