- Instruction addresses are now checked in the IF stage, after the cache
and after the prefetch buffer.
- To deal with unaligned instructions, the PMP logic checks the current
address and the next in parallel.
- The spec_branch timing hack has been removed as it's no longer
relevant with the PMP logic moved.
- Various updates made to the icache testbench to account for the
changes.
- Relates to #1471
Signed-off-by: Tom Roberts <tomroberts@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>
This commit contains some final optimizations regarding the bit
manipulation extension as well as the parametrization into a balanced
version and a full performance version.
Balanced Version:
* Supports ZBB, ZBS, ZBF and ZBT extensions
* Dual cycle instructions:
ror[i], rol, cmov, cmix fsl, fsr[i]
* Everything else completes in a single cycle.
Full Version:
* Supports all 32b sub extensions.
* Dual cycle instructions:
ror[i], rol, cmov, cmix fsl, fsr[i], crc32[c], bext, bdep
* Everything else completes in a single cycle.
Notable Changes:
* bext/bdep are now multi-cycle: Sharing additional register
with multiplier module
* grev/gorc instructions are implemented in separate structures
rather than sharing the shifter or butterfly network.
* Speed up decision on using rs1 or rs3 for alu_operand_a by
introducing single-bit register, to identify ternary
instructions in their first cycle.
* Introduce enumerated parameter to chose bit manipulation
implementation
Signed-off-by: ganoam <gnoam@live.com>
This commit helps to make the README.md the main entry point into the
Ibex world. It does so by updating it and including additional
references to a style guide, a guide on how to write commit messages,
references to our Zulip chat and the original Zero-riscy paper.
This commit was prepared by the following script, followed by manual
fixes as needed.
```sh
sed -e 's/zeroriscy/ibex/g' -i.bak *.sv *.md *.yml
sed -e 's/zero-riscy/ibex/g' -i.bak *.sv *.md *.yml
sed -e 's/zeroriscy/ibex/g' -i.bak include/*.sv
sed -e 's/zero-riscy/ibex/g' -i.bak include/*.sv
sed -e 's/cluster_clock_gating/clock_gating/g' -i.bak *.sv
rm -f *.bak
rm -f include/*.bak
find . -name 'zeroriscy_*' -exec bash -c 'file={}; git mv $file ${file/zeroriscy/ibex}' \;
```
