Clean up paragraph on FIRRTL transform BlackBox support

This commit is contained in:
Albert Magyar
2019-09-26 10:09:02 -07:00
parent 28664ea8df
commit f2939823ce

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@@ -17,7 +17,7 @@ algorithm. There are a few steps to adding a Verilog peripheral:
* Instantiating the ``BlackBox`` and interfacing ``RegField`` entries
* Setting up a chip ``Top`` and ``Config`` that use the peripheral
Adding a Verilog blackbox resource file
Adding a Verilog Blackbox Resource File
---------------------------------------
As before, it is possible to incorporate peripherals as part of your
@@ -112,7 +112,7 @@ previous memory-mapped PWM device example.
Advanced Features of RegField Entries
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
One signficant difference from the PWM example is in the peripheral's
One significant difference from the PWM example is in the peripheral's
memory map. ``RegField`` exposes polymorphic ``r`` and ``w`` methods
that allow read- and write-only memory-mapped registers to be
interfaced to hardware in multiple ways.
@@ -162,18 +162,23 @@ Support for Verilog Within Chipyard Tool Flows
----------------------------------------------
There are important differences in how Verilog blackboxes are treated
by downstream tools. Since they remain blackboxes in FIRRTL, their
ability to be processed by FIRRTL transforms is limited, and some
advanced features of Chipyard may provide weaker support for
blackboxes. Note that the remainder of the target design may still
generally be transformed or augmented by any Chipyard FIRRTL
transform.
by various flows within the Chipyard framework. Some flows within
Chipyard rely on FIRRTL in order to provide robust, non-invasive
transformations of source code. Since Verilog blackboxes remain
blackboxes in FIRRTL, their ability to be processed by FIRRTL
transforms is limited, and some advanced features of Chipyard may
provide weaker support for blackboxes. Note that the remainder of the
design (the "non-Verilog" part of the design) may still generally be
transformed or augmented by any Chipyard FIRRTL transform.
* Verilog blackboxes are fully supported for generating tapeout-ready RTL
* HAMMER workflows offer robust support for integrating Verilog blackboxes
* FireSim relies on FIRRTL transformations to generate a decoupled
FPGA simulator. Therefore, support for Verilog blackboxes in FireSim
is currently limited but rapidly evolving. Stay tuned!
* Custom FIRRTL transformations and analyses may sometimes be able to
handle blackbox Verilog, depending on the mechanism of the
particular transform
As mentioned earlier in this section, ``BlackBox`` resource files must
be integrated into the build process, so any project providing