From 17a8faf1bbbfce7659c2c8b59831475a43fbd535 Mon Sep 17 00:00:00 2001
From: h_vogt <h_vogt>
Date: Sat, 27 Aug 2016 23:07:02 +0200
Subject: [PATCH] add xspice digital model d_lut (digital n-input look-up table
 gate) provided by Tim Edwards

---
 src/xspice/icm/digital/d_lut/cfunc.mod  | 263 ++++++++++++++++++++++++
 src/xspice/icm/digital/d_lut/ifspec.ifs |  77 +++++++
 src/xspice/icm/digital/modpath.lst      |   1 +
 visualc/xspice/digital.vcxproj          |   4 +
 4 files changed, 345 insertions(+)
 create mode 100644 src/xspice/icm/digital/d_lut/cfunc.mod
 create mode 100644 src/xspice/icm/digital/d_lut/ifspec.ifs

diff --git a/src/xspice/icm/digital/d_lut/cfunc.mod b/src/xspice/icm/digital/d_lut/cfunc.mod
new file mode 100644
index 000000000..8c38e3ff3
--- /dev/null
+++ b/src/xspice/icm/digital/d_lut/cfunc.mod
@@ -0,0 +1,263 @@
+/*.......1.........2.........3.........4.........5.........6.........7.........8
+================================================================================
+
+FILE d_lut/cfunc.mod
+
+Copyright 2016
+efabless inc., San Jose, CA
+All Rights Reserved
+
+AUTHORS                      
+
+    25 Aug 2016     Tim Edwards
+
+
+SUMMARY
+
+    This file contains the functional description of the d_lut
+    code model.
+
+
+INTERFACES       
+
+    FILE                 ROUTINE CALLED     
+
+    CMevt.c              void *cm_event_alloc()
+                         void *cm_event_get_ptr()
+                         
+
+
+REFERENCED FILES
+
+    Inputs from and outputs to ARGS structure.
+                     
+
+NON-STANDARD FEATURES
+
+    NONE
+
+===============================================================================*/
+
+/*=== INCLUDE FILES ====================*/
+
+#include <stdio.h>
+#include <ctype.h>
+#include <math.h>
+#include <string.h>
+
+                                      
+
+/*=== CONSTANTS ========================*/
+
+
+
+
+/*=== MACROS ===========================*/
+
+
+
+  
+/*=== LOCAL VARIABLES & TYPEDEFS =======*/                         
+
+
+    
+           
+/*=== FUNCTION PROTOTYPE DEFINITIONS ===*/
+
+
+
+
+                   
+/*==============================================================================
+
+FUNCTION cm_d_lut()
+
+AUTHORS                      
+
+    25 Aug 2016     Tim Edwards
+
+SUMMARY
+
+    This function implements the d_lut code model.
+
+INTERFACES       
+
+    FILE                 ROUTINE CALLED     
+
+    CMevt.c              void *cm_event_alloc()
+                         void *cm_event_get_ptr()
+
+RETURNED VALUE
+    
+    Returns inputs and outputs via ARGS structure.
+
+GLOBAL VARIABLES
+    
+    NONE
+
+NON-STANDARD FEATURES
+
+    NONE
+
+==============================================================================*/
+
+/*=== CM_D_LUT ROUTINE ===*/
+
+/************************************************
+*      The following is the model for the       *
+*   digital n-input LUT gate			*
+*                                               *
+*   Created 8/25/16               Tim Edwards	*
+************************************************/
+
+
+void cm_d_lut(ARGS) 
+
+{
+    int		i,	/* generic loop counter index */
+		j,	/* lookup index bit value */
+		idx,	/* lookup index */
+		size,	/* number of input & output ports */
+		tablelen; /* length of table (2^size) */
+
+    char	*table_string;
+
+    Digital_State_t *out,      /* temporary output for buffers */
+                    *out_old,  /* previous output for buffers  */
+                    input,     /* temp storage for input bits  */    
+		    *lookup_table; /* lookup table */
+
+    /** Retrieve size value and compute table length... **/
+    size = PORT_SIZE(in);
+    tablelen = 1 << size;
+
+    /*** Setup required state variables ***/
+
+    if (INIT) {  /* initial pass */ 
+
+        /* allocate storage for the lookup table */
+	STATIC_VAR (locdata) = calloc(tablelen, sizeof(Digital_State_t));
+	lookup_table = STATIC_VAR (locdata);
+
+        /* allocate storage for the outputs */
+        cm_event_alloc(0, sizeof(Digital_State_t));
+        cm_event_alloc(1, size * sizeof(Digital_State_t));
+                  
+        /* set loading for inputs */
+        for (i=0; i<size; i++) LOAD(in[i]) = PARAM(input_load);
+
+        /* retrieve storage for the outputs */
+        out = out_old = (Digital_State_t *) cm_event_get_ptr(0,0);
+
+	/* read parameter string into lookup table */
+        table_string = PARAM(table_values);
+	for (idx = 0; idx < strlen(table_string); idx++) {
+	    if (idx == tablelen)
+		// If string is longer than 2^num_inputs, ignore
+		// the extra values at the end
+		break;
+	    if (table_string[idx] == '1')
+		lookup_table[idx] = ONE;
+	    else if (table_string[idx] == '0')
+		lookup_table[idx] = ZERO;
+	    else
+		lookup_table[idx] = UNKNOWN;
+	}
+	for (; idx < tablelen; idx++) {
+	    // If string is shorter than 2^num_inputs, fill
+	    // the remainder of the lookup table with UNKNOWN
+	    // values.
+	    lookup_table[idx] = UNKNOWN;
+	}
+    }
+    else {      /* Retrieve previous values */
+                                              
+        /* retrieve lookup table */
+	lookup_table = STATIC_VAR (locdata);
+
+        /* retrieve storage for the outputs */
+        out = (Digital_State_t *) cm_event_get_ptr(0,0);
+        out_old = (Digital_State_t *) cm_event_get_ptr(0,1);
+    }
+
+    /*** Calculate new output value based on inputs and table ***/
+
+    *out = ZERO;
+    j = 1;
+    idx = 0;
+    for (i = 0; i < size; i++) {
+
+        /* make sure this input isn't floating... */
+        if (PORT_NULL(in) == FALSE) {
+
+            /* use inputs to find index into lookup table */
+	    if ((input = INPUT_STATE(in[i])) == UNKNOWN) {
+		*out = UNKNOWN;
+		break;
+	    }
+	    else if (input == ONE) idx += j;
+	    j <<= 1;
+        }
+        else {
+            /* at least one port is floating...output is unknown */
+            *out = UNKNOWN;
+            break;
+        }
+    }       
+
+    if (*out != UNKNOWN) {
+       *out = lookup_table[idx];
+    }
+
+    /*** Determine analysis type and output appropriate values ***/
+
+    if (ANALYSIS == DC) {   /** DC analysis...output w/o delays **/
+                                  
+        OUTPUT_STATE(out) = *out;
+
+    }
+
+    else {      /** Transient Analysis **/
+
+
+        if ( *out != *out_old ) { /* output value is changing */
+
+            switch ( *out ) {
+                                                 
+            /* fall to zero value */
+            case 0: OUTPUT_STATE(out) = ZERO;
+                    OUTPUT_DELAY(out) = PARAM(fall_delay);
+                    break;
+    
+            /* rise to one value */
+            case 1: OUTPUT_STATE(out) = ONE;
+                    OUTPUT_DELAY(out) = PARAM(rise_delay);
+                    break;
+                                    
+            /* unknown output */
+            default:
+                    OUTPUT_STATE(out) = *out = UNKNOWN;
+    
+                    /* based on old value, add rise or fall delay */
+                    if (0 == *out_old) {  /* add rising delay */
+                        OUTPUT_DELAY(out) = PARAM(rise_delay);
+                    }
+                    else {                /* add falling delay */
+                        OUTPUT_DELAY(out) = PARAM(fall_delay);
+                    }   
+                    break;
+            }
+        }
+        else {                    /* output value not changing */
+            OUTPUT_CHANGED(out) = FALSE;
+        }
+    }
+
+    OUTPUT_STRENGTH(out) = STRONG;
+
+} 
+
+      
+
+
+
diff --git a/src/xspice/icm/digital/d_lut/ifspec.ifs b/src/xspice/icm/digital/d_lut/ifspec.ifs
new file mode 100644
index 000000000..ed1311b13
--- /dev/null
+++ b/src/xspice/icm/digital/d_lut/ifspec.ifs
@@ -0,0 +1,77 @@
+/*.......1.........2.........3.........4.........5.........6.........7.........8
+================================================================================
+Copyright 2016
+efabless inc., San Jose, CA
+All Rights Reserved
+
+AUTHORS                      
+
+    25 Aug 2016     Tim Edwards
+
+
+SUMMARY
+
+    This file contains the interface specification file for the 
+    digital d_lut code model.
+
+===============================================================================*/
+
+NAME_TABLE:
+
+
+C_Function_Name:       cm_d_lut
+Spice_Model_Name:      d_lut
+Description:           "digital n-input look-up table gate"
+
+
+PORT_TABLE:
+
+Port_Name:           in                 out
+Description:         "input"            "output"
+Direction:           in                 out
+Default_Type:        d                  d
+Allowed_Types:       [d]                [d]
+Vector:              yes                no
+Vector_Bounds:       [1 -]              -
+Null_Allowed:        no                 no
+
+
+PARAMETER_TABLE:
+
+Parameter_Name:     rise_delay                  fall_delay	
+Description:        "rise delay"                "fall delay"
+Data_Type:          real                        real   
+Default_Value:      1.0e-9                      1.0e-9  
+Limits:             [1e-12 -]                   [1e-12 -]       
+Vector:              no                          no
+Vector_Bounds:       -                           -
+Null_Allowed:       yes                         yes    
+
+
+PARAMETER_TABLE:
+
+Parameter_Name:     input_load
+Description:        "input load value (F)" 
+Data_Type:          real                          
+Default_Value:      1.0e-12                    
+Limits:             -                                 
+Vector:              no                         
+Vector_Bounds:       -                         
+Null_Allowed:       yes                            
+
+PARAMETER_TABLE:
+
+Parameter_Name:     table_values
+Description:        "lookup table values" 
+Data_Type:          string
+Default_Value:      "0"
+Limits:             -                                 
+Vector:              no                         
+Vector_Bounds:       -                         
+Null_Allowed:       no
+
+STATIC_VAR_TABLE:
+
+Static_Var_Name:    locdata
+Description:        "lookup table"
+Data_Type:          pointer
diff --git a/src/xspice/icm/digital/modpath.lst b/src/xspice/icm/digital/modpath.lst
index 075678bf3..56b104c8a 100644
--- a/src/xspice/icm/digital/modpath.lst
+++ b/src/xspice/icm/digital/modpath.lst
@@ -7,6 +7,7 @@ d_dlatch
 d_fdiv
 d_inverter
 d_jkff
+d_lut
 d_nand
 d_nor
 d_open_c
diff --git a/visualc/xspice/digital.vcxproj b/visualc/xspice/digital.vcxproj
index ce1c4c656..5449531ad 100644
--- a/visualc/xspice/digital.vcxproj
+++ b/visualc/xspice/digital.vcxproj
@@ -239,6 +239,8 @@
       <AdditionalIncludeDirectories>..\..\src\xspice\%(RelativeDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
     </ClCompile>
     <ClCompile Include="icm\digital\d_jkff\d_jkff-ifspec.c" />
+    <ClCompile Include="icm\digital\d_lut\d_lut-cfunc.c" />
+    <ClCompile Include="icm\digital\d_lut\d_lut-ifspec.c" />
     <ClCompile Include="icm\digital\d_nand\d_nand-cfunc.c">
       <AdditionalIncludeDirectories>..\..\src\xspice\%(RelativeDir);%(AdditionalIncludeDirectories)</AdditionalIncludeDirectories>
     </ClCompile>
@@ -328,6 +330,8 @@
     <None Include="..\..\src\xspice\icm\digital\d_inverter\ifspec.ifs" />
     <None Include="..\..\src\xspice\icm\digital\d_jkff\cfunc.mod" />
     <None Include="..\..\src\xspice\icm\digital\d_jkff\ifspec.ifs" />
+    <None Include="..\..\src\xspice\icm\digital\d_lut\cfunc.mod" />
+    <None Include="..\..\src\xspice\icm\digital\d_lut\ifspec.ifs" />
     <None Include="..\..\src\xspice\icm\digital\d_nand\cfunc.mod" />
     <None Include="..\..\src\xspice\icm\digital\d_nand\ifspec.ifs" />
     <None Include="..\..\src\xspice\icm\digital\d_nor\cfunc.mod" />