Update logic.rst

Author: MahirAbbas

source/SpinalHDL/Libraries/logic.rst

@@ -1,33 +1,37 @@
-Logic Simplification Utilities 
+Logic Simplification Utilities and Decoder 
 ===============================
 A minimal Boolean simplification and decode-table utility for decoders using quine-mcklusky. 
 Provides masked pattern matching, Quine McCluskey style logic reduction, and a high-level decode-table builder. 
 --- # Masked 
 Represents a bit pattern with care (significant) and don't-care bits. 
 `value` = bit values 
 `care` = which bits must match (1 = match, 0 = don't care) 
-**Main API:** 
-* `covers(that)` check if one pattern includes another 
-* `intersects(that)` check if patterns overlap 
-* `mergeOneBitDifSmaller` merge patterns differing by one bit 
-* `=== (bits)` hardware match under mask 
-* `toString(bitCount)` shows bits with - for don't-care 
-**Example:** 
+--- Example:
+
+.. code-block:: scala 
+  Masked(0010), 
+  Masked(11-1), 
+  Masked(1--0) 
+
+e.g RISC-V instrs
+
 .. code-block:: scala 
-  Masked(BigInt("0010", 2), Masked("1111", 2)), Masked(1--0) 
+  val ADD     = M"0000000----------000-----0110011"
+  val ADDI    = M"-----------------000-----0010011"
   
 Used to define instruction encodings for decode tables. 
---- # Symplify Performs Boolean logic minimization for decode circuits. 
-**Main API:** 
-* `apply(input, mapping, resultWidth)` simplified decode logic 
-* `apply(input, trueTerms)` simplified Boolean output 
-* `trueAndDontCare(...)` simplified Boolean with explicit don-t-care terms Based on Quine McCluskey; runs at elaboration time. 
-
---- # DecodingSpec High-level builder for decode tables using `Masked` patterns. 
-  **API:** * `setDefault(value)` 
-  * `addNeeds(key, value)` 
-  * `addNeeds(keys, value)` 
-  * `build(sel, coverAll)` 
+
+
+--- # DecodingSpec 
+High-level builder for decode tables using `Masked` patterns. 
+`` val decoder = new DecodingSpec()
+  **API:** 
+
+  * `addNeeds(key : Masked, value : Masked)` 
+  * `addNeeds(keys : Seq[Masked], value : Masked)` 
+  * `build(sel, coverAll)`
+  * ``def setDefault(value : Masked)``
+
   generate simplified decode logic 
 **Example:** 
 .. code-block:: scala ``` 
@@ -38,6 +42,6 @@ Used to define instruction encodings for decode tables.
 
 Generates minimized combinational decode logic. 
   --- # Practical Use 
-Define bit patterns as `Masked` and feed them into `DecodingSpec` or `Symplify` to build compact decode logic for CPU instruction sets (e.g., RISC-V). 
+Define bit patterns as `Masked` and feed them into `DecodingSpec` to build compact decode logic (e.g., RISC-V). 
 
 * Output hardware is minimized (fewer LUTs / simpler gates)