Differences

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--- history:start [2023/02/26 13:35] – rajit
+++ history:start [2025/06/18 16:43] (current) – [Current language features] rajit
@@ Line 1: / Line 1: @@
 ====== Language history ======
-This is a rough chronology of the development/evolution of ACT.
+This is a rough chronology of the influences from the literature on the ACT language.
    * 1975 E.W. Dijkstra's paper on a guarded command language appears in CACM
@@ Line 8: / Line 8: @@
    * 1988-89: The [[https://authors.library.caltech.edu/26709/2/postscript.pdf|first asynchronous microprocessor]] was designed and fabricated at Caltech.
-Language development:
+===== Language development =====
-   * ~1991 (?), a language for hierarchical production rules was developed at Caltech (A.J. Martin's group). This was dubbed "CAST" for Caltech Asynchronous Synthesis Tools. A snippet of a circuit in this language is shown below:
+This is a rough chronology of the development/evolution of ACT upto the current version of the language.
+   * ~1991 (?), a language for hierarchical production rules was developed at Caltech (A.J. Martin's group) based on their experience with designing the first asynchronous microprocessor. This was dubbed "CAST" for Caltech Asynchronous Synthesis Tools. A snippet of a circuit in this language is shown below:
 <code>
 define prs (a)f()
@@ Line 19: / Line 21: @@
 cell (_)f()
 </code>
-   * 1995, a new CAST language ({{ :history:cast.pdf |docs}}) was developed from scratch and implemented by [[http://csl.yale.edu/~rajit|Rajit Manohar]] (at the time a graduate student in A.J. Martin's group).
+   * 1995, a new CAST language ({{ :history:cast.pdf |docs}}) was developed from scratch and implemented by [[http://csl.yale.edu/~rajit|Rajit Manohar]] (at the time a graduate student in A.J. Martin's group). The same example as above would be written as follows in the new CAST syntax
+<code>
+define f (node a)
+{  node p, q;
+   prs {
+       p -> q+
+    }
+   a = p;
+ }
+f();
+</code>
    * 1995-1998 CAST was used to implement the [[https://csl.yale.edu/~rajit/ps/minimips.pdf|first high-performance asynchronous microprocessor]].
    * ~1998 Andrew Lines and Uri Cummings from Martin's group at Caltech launch startup Asynchronous Digital Design (later renamed to Fulcrum Microsystems), which licenses the tools developed at Caltech. Over the years, Fulcrum develops more CAST tools for internal commercial use, including proprietary language extensions.
@@ Line 25: / Line 37: @@
    * 1998-2003 Development continued at Caltech, including embedding CAST-like syntax within the Modula-3 language. This version was used to design the Lutonium processor.
    * 2004 A language that provided the same functionality as CAST but with syntax for new features (not implemented) was developed at Cornell by Rajit Manohar, based on lessons from using CAST for chip design. This was called ACT (version 0; 0 because the new features were not supported yet)
-   * 2005-2008 ACT v0 was used by Achronix Semiconductor, a startup company founded by Rajit Manohar along with some of his Ph.D. students.
+   * 2005-2008 ACT v0 was used by Achronix Semiconductor, a startup company founded by Rajit Manohar along with some of his Ph.D. students. The same example above would be specified as follows in ACT v0.
+<code>
+defproc f (bool a)
+{  bool p, q;
+   prs {
+       p -> q+
+    }
+   a = p;
+ }
+f dummy;
+</code>
    * 2005-2010 An open-source (GPLed) implementation of an ACT v0 variant (called "HACKT") was developed by David Fang (student in Rajit Manohar's group) as part of his Ph.D. dissertation.
    * 2005-2014: ACT was used to implement a large number of asynchronous chips, including microprocessors, FPGAs, a GPS baseband engine, digital circuits in continuous-time signal processing hardware, neuromorphic hardware, etc.
@@ Line 32: / Line 54: @@
    * 2012, Intel acquires Fulcrum Microsystems, as well as the version of the CAST tools developed by Fulcrum.
    * 2017, actual implementation of the new features started at Yale with a fresh implementation of the entire system.
-   * 2018, Most features of ACT v1 ready
+   * 2018, Most features of ACT v1 ready. The example above would be defined as follows:
+<code act>
+defproc f (bool? a)
+{  bool p, q;
+   prs {
+       p -> q+
+    }
+   a = p;
+ }
+f dummy;
+</code>
    * 1/2019, first [[http://github.com/asyncvlsi/act|open-source release]]
    * 4/2019, documentation effort initiated
-   * 2019, first prototype of static timing analysis for asynchronous logic
-   * 2020, support for LEF/DEF exports
+===== Current language features =====
-   * 2020, first prototype of ''chp2prs'' (syntax-directed translation)
-   * 2020-2022, placement and routing flow developed
+Evolution of ACT Language features (current version):
-   * 2020-2022, dataflow synthesis flow developed
-   * 2021-2023, timing-driven flow developed
+  * 1/2019: support for production rules and netlist generation
+  * 1/2021: support for CHP simulation
+  * 1/2022: support for mixed-signal simulation with ''Xyce''
+  * 1/2023: trace file generation
+  * 1/2024: support for structures
+  * 1/2025: support for methods
+  * 6/2025: support for SDF and multi-driver production rules