ams-vhdl: add frequency function, minor fixes.

7 files changed, 207 insertions, 186 deletions

diff --git a/python/libghdl/thin/vhdl/nodes.py b/python/libghdl/thin/vhdl/nodes.py
index 06c9a750b..dce74a709 100644
--- a/python/libghdl/thin/vhdl/nodes.py
+++ b/python/libghdl/thin/vhdl/nodes.py
@@ -1136,186 +1136,187 @@ class Iir_Predefined:
     Endfile = 169
     Now_Function = 170
     Real_Now_Function = 171
-    PNone = 172
-    Foreign_Untruncated_Text_Read = 173
-    Foreign_Textio_Read_Real = 174
-    Foreign_Textio_Write_Real = 175
-    Ieee_1164_Scalar_And = 176
-    Ieee_1164_Scalar_Nand = 177
-    Ieee_1164_Scalar_Or = 178
-    Ieee_1164_Scalar_Nor = 179
-    Ieee_1164_Scalar_Xor = 180
-    Ieee_1164_Scalar_Xnor = 181
-    Ieee_1164_Scalar_Not = 182
-    Ieee_1164_Vector_And = 183
-    Ieee_1164_Vector_Nand = 184
-    Ieee_1164_Vector_Or = 185
-    Ieee_1164_Vector_Nor = 186
-    Ieee_1164_Vector_Xor = 187
-    Ieee_1164_Vector_Xnor = 188
-    Ieee_1164_Vector_Not = 189
-    Ieee_1164_To_Bitvector = 190
-    Ieee_1164_Vector_Is_X = 191
-    Ieee_1164_Scalar_Is_X = 192
-    Ieee_1164_Rising_Edge = 193
-    Ieee_1164_Falling_Edge = 194
-    Ieee_1164_Vector_And_Reduce = 195
-    Ieee_1164_Vector_Or_Reduce = 196
-    Ieee_1164_Condition_Operator = 197
-    Ieee_Numeric_Std_Toint_Uns_Nat = 198
-    Ieee_Numeric_Std_Toint_Sgn_Int = 199
-    Ieee_Numeric_Std_Touns_Nat_Nat_Uns = 200
-    Ieee_Numeric_Std_Touns_Nat_Uns_Uns = 201
-    Ieee_Numeric_Std_Tosgn_Int_Nat_Sgn = 202
-    Ieee_Numeric_Std_Tosgn_Int_Sgn_Sgn = 203
-    Ieee_Numeric_Std_Resize_Uns_Nat = 204
-    Ieee_Numeric_Std_Resize_Sgn_Nat = 205
-    Ieee_Numeric_Std_Resize_Uns_Uns = 206
-    Ieee_Numeric_Std_Resize_Sgn_Sgn = 207
-    Ieee_Numeric_Std_Add_Uns_Uns = 208
-    Ieee_Numeric_Std_Add_Uns_Nat = 209
-    Ieee_Numeric_Std_Add_Nat_Uns = 210
-    Ieee_Numeric_Std_Add_Uns_Log = 211
-    Ieee_Numeric_Std_Add_Log_Uns = 212
-    Ieee_Numeric_Std_Add_Sgn_Sgn = 213
-    Ieee_Numeric_Std_Add_Sgn_Int = 214
-    Ieee_Numeric_Std_Add_Int_Sgn = 215
-    Ieee_Numeric_Std_Add_Sgn_Log = 216
-    Ieee_Numeric_Std_Add_Log_Sgn = 217
-    Ieee_Numeric_Std_Sub_Uns_Uns = 218
-    Ieee_Numeric_Std_Sub_Uns_Nat = 219
-    Ieee_Numeric_Std_Sub_Nat_Uns = 220
-    Ieee_Numeric_Std_Sub_Sgn_Sgn = 221
-    Ieee_Numeric_Std_Sub_Sgn_Int = 222
-    Ieee_Numeric_Std_Sub_Int_Sgn = 223
-    Ieee_Numeric_Std_Mul_Uns_Uns = 224
-    Ieee_Numeric_Std_Mul_Uns_Nat = 225
-    Ieee_Numeric_Std_Mul_Nat_Uns = 226
-    Ieee_Numeric_Std_Mul_Sgn_Sgn = 227
-    Ieee_Numeric_Std_Mul_Sgn_Int = 228
-    Ieee_Numeric_Std_Mul_Int_Sgn = 229
-    Ieee_Numeric_Std_Div_Uns_Uns = 230
-    Ieee_Numeric_Std_Div_Uns_Nat = 231
-    Ieee_Numeric_Std_Div_Nat_Uns = 232
-    Ieee_Numeric_Std_Div_Sgn_Sgn = 233
-    Ieee_Numeric_Std_Div_Sgn_Int = 234
-    Ieee_Numeric_Std_Div_Int_Sgn = 235
-    Ieee_Numeric_Std_Gt_Uns_Uns = 236
-    Ieee_Numeric_Std_Gt_Uns_Nat = 237
-    Ieee_Numeric_Std_Gt_Nat_Uns = 238
-    Ieee_Numeric_Std_Gt_Sgn_Sgn = 239
-    Ieee_Numeric_Std_Gt_Sgn_Int = 240
-    Ieee_Numeric_Std_Gt_Int_Sgn = 241
-    Ieee_Numeric_Std_Lt_Uns_Uns = 242
-    Ieee_Numeric_Std_Lt_Uns_Nat = 243
-    Ieee_Numeric_Std_Lt_Nat_Uns = 244
-    Ieee_Numeric_Std_Lt_Sgn_Sgn = 245
-    Ieee_Numeric_Std_Lt_Sgn_Int = 246
-    Ieee_Numeric_Std_Lt_Int_Sgn = 247
-    Ieee_Numeric_Std_Le_Uns_Uns = 248
-    Ieee_Numeric_Std_Le_Uns_Nat = 249
-    Ieee_Numeric_Std_Le_Nat_Uns = 250
-    Ieee_Numeric_Std_Le_Sgn_Sgn = 251
-    Ieee_Numeric_Std_Le_Sgn_Int = 252
-    Ieee_Numeric_Std_Le_Int_Sgn = 253
-    Ieee_Numeric_Std_Ge_Uns_Uns = 254
-    Ieee_Numeric_Std_Ge_Uns_Nat = 255
-    Ieee_Numeric_Std_Ge_Nat_Uns = 256
-    Ieee_Numeric_Std_Ge_Sgn_Sgn = 257
-    Ieee_Numeric_Std_Ge_Sgn_Int = 258
-    Ieee_Numeric_Std_Ge_Int_Sgn = 259
-    Ieee_Numeric_Std_Eq_Uns_Uns = 260
-    Ieee_Numeric_Std_Eq_Uns_Nat = 261
-    Ieee_Numeric_Std_Eq_Nat_Uns = 262
-    Ieee_Numeric_Std_Eq_Sgn_Sgn = 263
-    Ieee_Numeric_Std_Eq_Sgn_Int = 264
-    Ieee_Numeric_Std_Eq_Int_Sgn = 265
-    Ieee_Numeric_Std_Ne_Uns_Uns = 266
-    Ieee_Numeric_Std_Ne_Uns_Nat = 267
-    Ieee_Numeric_Std_Ne_Nat_Uns = 268
-    Ieee_Numeric_Std_Ne_Sgn_Sgn = 269
-    Ieee_Numeric_Std_Ne_Sgn_Int = 270
-    Ieee_Numeric_Std_Ne_Int_Sgn = 271
-    Ieee_Numeric_Std_Shl_Uns_Nat = 272
-    Ieee_Numeric_Std_Shr_Uns_Nat = 273
-    Ieee_Numeric_Std_Shl_Sgn_Nat = 274
-    Ieee_Numeric_Std_Shr_Sgn_Nat = 275
-    Ieee_Numeric_Std_Rol_Uns_Nat = 276
-    Ieee_Numeric_Std_Ror_Uns_Nat = 277
-    Ieee_Numeric_Std_Rol_Sgn_Nat = 278
-    Ieee_Numeric_Std_Ror_Sgn_Nat = 279
-    Ieee_Numeric_Std_Not_Uns = 280
-    Ieee_Numeric_Std_Not_Sgn = 281
-    Ieee_Numeric_Std_And_Uns_Uns = 282
-    Ieee_Numeric_Std_And_Sgn_Sgn = 283
-    Ieee_Numeric_Std_Or_Uns_Uns = 284
-    Ieee_Numeric_Std_Or_Sgn_Sgn = 285
-    Ieee_Numeric_Std_Nand_Uns_Uns = 286
-    Ieee_Numeric_Std_Nand_Sgn_Sgn = 287
-    Ieee_Numeric_Std_Nor_Uns_Uns = 288
-    Ieee_Numeric_Std_Nor_Sgn_Sgn = 289
-    Ieee_Numeric_Std_Xor_Uns_Uns = 290
-    Ieee_Numeric_Std_Xor_Sgn_Sgn = 291
-    Ieee_Numeric_Std_Xnor_Uns_Uns = 292
-    Ieee_Numeric_Std_Xnor_Sgn_Sgn = 293
-    Ieee_Numeric_Std_Neg_Uns = 294
-    Ieee_Numeric_Std_Neg_Sgn = 295
-    Ieee_Numeric_Std_Match_Log = 296
-    Ieee_Numeric_Std_Match_Uns = 297
-    Ieee_Numeric_Std_Match_Sgn = 298
-    Ieee_Numeric_Std_Match_Slv = 299
-    Ieee_Numeric_Std_Match_Suv = 300
-    Ieee_Math_Real_Ceil = 301
-    Ieee_Math_Real_Log2 = 302
-    Ieee_Math_Real_Sin = 303
-    Ieee_Math_Real_Cos = 304
-    Ieee_Std_Logic_Unsigned_Add_Slv_Slv = 305
-    Ieee_Std_Logic_Unsigned_Add_Slv_Int = 306
-    Ieee_Std_Logic_Unsigned_Add_Int_Slv = 307
-    Ieee_Std_Logic_Unsigned_Add_Slv_Sl = 308
-    Ieee_Std_Logic_Unsigned_Add_Sl_Slv = 309
-    Ieee_Std_Logic_Unsigned_Sub_Slv_Slv = 310
-    Ieee_Std_Logic_Unsigned_Sub_Slv_Int = 311
-    Ieee_Std_Logic_Unsigned_Sub_Int_Slv = 312
-    Ieee_Std_Logic_Unsigned_Sub_Slv_Sl = 313
-    Ieee_Std_Logic_Unsigned_Sub_Sl_Slv = 314
-    Ieee_Std_Logic_Unsigned_Lt_Slv_Slv = 315
-    Ieee_Std_Logic_Unsigned_Lt_Slv_Int = 316
-    Ieee_Std_Logic_Unsigned_Lt_Int_Slv = 317
-    Ieee_Std_Logic_Unsigned_Le_Slv_Slv = 318
-    Ieee_Std_Logic_Unsigned_Le_Slv_Int = 319
-    Ieee_Std_Logic_Unsigned_Le_Int_Slv = 320
-    Ieee_Std_Logic_Unsigned_Gt_Slv_Slv = 321
-    Ieee_Std_Logic_Unsigned_Gt_Slv_Int = 322
-    Ieee_Std_Logic_Unsigned_Gt_Int_Slv = 323
-    Ieee_Std_Logic_Unsigned_Ge_Slv_Slv = 324
-    Ieee_Std_Logic_Unsigned_Ge_Slv_Int = 325
-    Ieee_Std_Logic_Unsigned_Ge_Int_Slv = 326
-    Ieee_Std_Logic_Unsigned_Eq_Slv_Slv = 327
-    Ieee_Std_Logic_Unsigned_Eq_Slv_Int = 328
-    Ieee_Std_Logic_Unsigned_Eq_Int_Slv = 329
-    Ieee_Std_Logic_Unsigned_Ne_Slv_Slv = 330
-    Ieee_Std_Logic_Unsigned_Ne_Slv_Int = 331
-    Ieee_Std_Logic_Unsigned_Ne_Int_Slv = 332
-    Ieee_Std_Logic_Unsigned_Conv_Integer = 333
-    Ieee_Std_Logic_Signed_Add_Slv_Slv = 334
-    Ieee_Std_Logic_Signed_Add_Slv_Int = 335
-    Ieee_Std_Logic_Signed_Add_Int_Slv = 336
-    Ieee_Std_Logic_Signed_Add_Slv_Sl = 337
-    Ieee_Std_Logic_Signed_Add_Sl_Slv = 338
-    Ieee_Std_Logic_Signed_Sub_Slv_Slv = 339
-    Ieee_Std_Logic_Signed_Sub_Slv_Int = 340
-    Ieee_Std_Logic_Signed_Sub_Int_Slv = 341
-    Ieee_Std_Logic_Signed_Sub_Slv_Sl = 342
-    Ieee_Std_Logic_Signed_Sub_Sl_Slv = 343
-    Ieee_Std_Logic_Arith_Conv_Unsigned_Int = 344
-    Ieee_Std_Logic_Arith_Conv_Unsigned_Uns = 345
-    Ieee_Std_Logic_Arith_Conv_Unsigned_Sgn = 346
-    Ieee_Std_Logic_Arith_Conv_Unsigned_Log = 347
-    Ieee_Std_Logic_Arith_Conv_Integer_Int = 348
-    Ieee_Std_Logic_Arith_Conv_Integer_Uns = 349
-    Ieee_Std_Logic_Arith_Conv_Integer_Sgn = 350
-    Ieee_Std_Logic_Arith_Conv_Integer_Log = 351
+    Frequency_Function = 172
+    PNone = 173
+    Foreign_Untruncated_Text_Read = 174
+    Foreign_Textio_Read_Real = 175
+    Foreign_Textio_Write_Real = 176
+    Ieee_1164_Scalar_And = 177
+    Ieee_1164_Scalar_Nand = 178
+    Ieee_1164_Scalar_Or = 179
+    Ieee_1164_Scalar_Nor = 180
+    Ieee_1164_Scalar_Xor = 181
+    Ieee_1164_Scalar_Xnor = 182
+    Ieee_1164_Scalar_Not = 183
+    Ieee_1164_Vector_And = 184
+    Ieee_1164_Vector_Nand = 185
+    Ieee_1164_Vector_Or = 186
+    Ieee_1164_Vector_Nor = 187
+    Ieee_1164_Vector_Xor = 188
+    Ieee_1164_Vector_Xnor = 189
+    Ieee_1164_Vector_Not = 190
+    Ieee_1164_To_Bitvector = 191
+    Ieee_1164_Vector_Is_X = 192
+    Ieee_1164_Scalar_Is_X = 193
+    Ieee_1164_Rising_Edge = 194
+    Ieee_1164_Falling_Edge = 195
+    Ieee_1164_Vector_And_Reduce = 196
+    Ieee_1164_Vector_Or_Reduce = 197
+    Ieee_1164_Condition_Operator = 198
+    Ieee_Numeric_Std_Toint_Uns_Nat = 199
+    Ieee_Numeric_Std_Toint_Sgn_Int = 200
+    Ieee_Numeric_Std_Touns_Nat_Nat_Uns = 201
+    Ieee_Numeric_Std_Touns_Nat_Uns_Uns = 202
+    Ieee_Numeric_Std_Tosgn_Int_Nat_Sgn = 203
+    Ieee_Numeric_Std_Tosgn_Int_Sgn_Sgn = 204
+    Ieee_Numeric_Std_Resize_Uns_Nat = 205
+    Ieee_Numeric_Std_Resize_Sgn_Nat = 206
+    Ieee_Numeric_Std_Resize_Uns_Uns = 207
+    Ieee_Numeric_Std_Resize_Sgn_Sgn = 208
+    Ieee_Numeric_Std_Add_Uns_Uns = 209
+    Ieee_Numeric_Std_Add_Uns_Nat = 210
+    Ieee_Numeric_Std_Add_Nat_Uns = 211
+    Ieee_Numeric_Std_Add_Uns_Log = 212
+    Ieee_Numeric_Std_Add_Log_Uns = 213
+    Ieee_Numeric_Std_Add_Sgn_Sgn = 214
+    Ieee_Numeric_Std_Add_Sgn_Int = 215
+    Ieee_Numeric_Std_Add_Int_Sgn = 216
+    Ieee_Numeric_Std_Add_Sgn_Log = 217
+    Ieee_Numeric_Std_Add_Log_Sgn = 218
+    Ieee_Numeric_Std_Sub_Uns_Uns = 219
+    Ieee_Numeric_Std_Sub_Uns_Nat = 220
+    Ieee_Numeric_Std_Sub_Nat_Uns = 221
+    Ieee_Numeric_Std_Sub_Sgn_Sgn = 222
+    Ieee_Numeric_Std_Sub_Sgn_Int = 223
+    Ieee_Numeric_Std_Sub_Int_Sgn = 224
+    Ieee_Numeric_Std_Mul_Uns_Uns = 225
+    Ieee_Numeric_Std_Mul_Uns_Nat = 226
+    Ieee_Numeric_Std_Mul_Nat_Uns = 227
+    Ieee_Numeric_Std_Mul_Sgn_Sgn = 228
+    Ieee_Numeric_Std_Mul_Sgn_Int = 229
+    Ieee_Numeric_Std_Mul_Int_Sgn = 230
+    Ieee_Numeric_Std_Div_Uns_Uns = 231
+    Ieee_Numeric_Std_Div_Uns_Nat = 232
+    Ieee_Numeric_Std_Div_Nat_Uns = 233
+    Ieee_Numeric_Std_Div_Sgn_Sgn = 234
+    Ieee_Numeric_Std_Div_Sgn_Int = 235
+    Ieee_Numeric_Std_Div_Int_Sgn = 236
+    Ieee_Numeric_Std_Gt_Uns_Uns = 237
+    Ieee_Numeric_Std_Gt_Uns_Nat = 238
+    Ieee_Numeric_Std_Gt_Nat_Uns = 239
+    Ieee_Numeric_Std_Gt_Sgn_Sgn = 240
+    Ieee_Numeric_Std_Gt_Sgn_Int = 241
+    Ieee_Numeric_Std_Gt_Int_Sgn = 242
+    Ieee_Numeric_Std_Lt_Uns_Uns = 243
+    Ieee_Numeric_Std_Lt_Uns_Nat = 244
+    Ieee_Numeric_Std_Lt_Nat_Uns = 245
+    Ieee_Numeric_Std_Lt_Sgn_Sgn = 246
+    Ieee_Numeric_Std_Lt_Sgn_Int = 247
+    Ieee_Numeric_Std_Lt_Int_Sgn = 248
+    Ieee_Numeric_Std_Le_Uns_Uns = 249
+    Ieee_Numeric_Std_Le_Uns_Nat = 250
+    Ieee_Numeric_Std_Le_Nat_Uns = 251
+    Ieee_Numeric_Std_Le_Sgn_Sgn = 252
+    Ieee_Numeric_Std_Le_Sgn_Int = 253
+    Ieee_Numeric_Std_Le_Int_Sgn = 254
+    Ieee_Numeric_Std_Ge_Uns_Uns = 255
+    Ieee_Numeric_Std_Ge_Uns_Nat = 256
+    Ieee_Numeric_Std_Ge_Nat_Uns = 257
+    Ieee_Numeric_Std_Ge_Sgn_Sgn = 258
+    Ieee_Numeric_Std_Ge_Sgn_Int = 259
+    Ieee_Numeric_Std_Ge_Int_Sgn = 260
+    Ieee_Numeric_Std_Eq_Uns_Uns = 261
+    Ieee_Numeric_Std_Eq_Uns_Nat = 262
+    Ieee_Numeric_Std_Eq_Nat_Uns = 263
+    Ieee_Numeric_Std_Eq_Sgn_Sgn = 264
+    Ieee_Numeric_Std_Eq_Sgn_Int = 265
+    Ieee_Numeric_Std_Eq_Int_Sgn = 266
+    Ieee_Numeric_Std_Ne_Uns_Uns = 267
+    Ieee_Numeric_Std_Ne_Uns_Nat = 268
+    Ieee_Numeric_Std_Ne_Nat_Uns = 269
+    Ieee_Numeric_Std_Ne_Sgn_Sgn = 270
+    Ieee_Numeric_Std_Ne_Sgn_Int = 271
+    Ieee_Numeric_Std_Ne_Int_Sgn = 272
+    Ieee_Numeric_Std_Shl_Uns_Nat = 273
+    Ieee_Numeric_Std_Shr_Uns_Nat = 274
+    Ieee_Numeric_Std_Shl_Sgn_Nat = 275
+    Ieee_Numeric_Std_Shr_Sgn_Nat = 276
+    Ieee_Numeric_Std_Rol_Uns_Nat = 277
+    Ieee_Numeric_Std_Ror_Uns_Nat = 278
+    Ieee_Numeric_Std_Rol_Sgn_Nat = 279
+    Ieee_Numeric_Std_Ror_Sgn_Nat = 280
+    Ieee_Numeric_Std_Not_Uns = 281
+    Ieee_Numeric_Std_Not_Sgn = 282
+    Ieee_Numeric_Std_And_Uns_Uns = 283
+    Ieee_Numeric_Std_And_Sgn_Sgn = 284
+    Ieee_Numeric_Std_Or_Uns_Uns = 285
+    Ieee_Numeric_Std_Or_Sgn_Sgn = 286
+    Ieee_Numeric_Std_Nand_Uns_Uns = 287
+    Ieee_Numeric_Std_Nand_Sgn_Sgn = 288
+    Ieee_Numeric_Std_Nor_Uns_Uns = 289
+    Ieee_Numeric_Std_Nor_Sgn_Sgn = 290
+    Ieee_Numeric_Std_Xor_Uns_Uns = 291
+    Ieee_Numeric_Std_Xor_Sgn_Sgn = 292
+    Ieee_Numeric_Std_Xnor_Uns_Uns = 293
+    Ieee_Numeric_Std_Xnor_Sgn_Sgn = 294
+    Ieee_Numeric_Std_Neg_Uns = 295
+    Ieee_Numeric_Std_Neg_Sgn = 296
+    Ieee_Numeric_Std_Match_Log = 297
+    Ieee_Numeric_Std_Match_Uns = 298
+    Ieee_Numeric_Std_Match_Sgn = 299
+    Ieee_Numeric_Std_Match_Slv = 300
+    Ieee_Numeric_Std_Match_Suv = 301
+    Ieee_Math_Real_Ceil = 302
+    Ieee_Math_Real_Log2 = 303
+    Ieee_Math_Real_Sin = 304
+    Ieee_Math_Real_Cos = 305
+    Ieee_Std_Logic_Unsigned_Add_Slv_Slv = 306
+    Ieee_Std_Logic_Unsigned_Add_Slv_Int = 307
+    Ieee_Std_Logic_Unsigned_Add_Int_Slv = 308
+    Ieee_Std_Logic_Unsigned_Add_Slv_Sl = 309
+    Ieee_Std_Logic_Unsigned_Add_Sl_Slv = 310
+    Ieee_Std_Logic_Unsigned_Sub_Slv_Slv = 311
+    Ieee_Std_Logic_Unsigned_Sub_Slv_Int = 312
+    Ieee_Std_Logic_Unsigned_Sub_Int_Slv = 313
+    Ieee_Std_Logic_Unsigned_Sub_Slv_Sl = 314
+    Ieee_Std_Logic_Unsigned_Sub_Sl_Slv = 315
+    Ieee_Std_Logic_Unsigned_Lt_Slv_Slv = 316
+    Ieee_Std_Logic_Unsigned_Lt_Slv_Int = 317
+    Ieee_Std_Logic_Unsigned_Lt_Int_Slv = 318
+    Ieee_Std_Logic_Unsigned_Le_Slv_Slv = 319
+    Ieee_Std_Logic_Unsigned_Le_Slv_Int = 320
+    Ieee_Std_Logic_Unsigned_Le_Int_Slv = 321
+    Ieee_Std_Logic_Unsigned_Gt_Slv_Slv = 322
+    Ieee_Std_Logic_Unsigned_Gt_Slv_Int = 323
+    Ieee_Std_Logic_Unsigned_Gt_Int_Slv = 324
+    Ieee_Std_Logic_Unsigned_Ge_Slv_Slv = 325
+    Ieee_Std_Logic_Unsigned_Ge_Slv_Int = 326
+    Ieee_Std_Logic_Unsigned_Ge_Int_Slv = 327
+    Ieee_Std_Logic_Unsigned_Eq_Slv_Slv = 328
+    Ieee_Std_Logic_Unsigned_Eq_Slv_Int = 329
+    Ieee_Std_Logic_Unsigned_Eq_Int_Slv = 330
+    Ieee_Std_Logic_Unsigned_Ne_Slv_Slv = 331
+    Ieee_Std_Logic_Unsigned_Ne_Slv_Int = 332
+    Ieee_Std_Logic_Unsigned_Ne_Int_Slv = 333
+    Ieee_Std_Logic_Unsigned_Conv_Integer = 334
+    Ieee_Std_Logic_Signed_Add_Slv_Slv = 335
+    Ieee_Std_Logic_Signed_Add_Slv_Int = 336
+    Ieee_Std_Logic_Signed_Add_Int_Slv = 337
+    Ieee_Std_Logic_Signed_Add_Slv_Sl = 338
+    Ieee_Std_Logic_Signed_Add_Sl_Slv = 339
+    Ieee_Std_Logic_Signed_Sub_Slv_Slv = 340
+    Ieee_Std_Logic_Signed_Sub_Slv_Int = 341
+    Ieee_Std_Logic_Signed_Sub_Int_Slv = 342
+    Ieee_Std_Logic_Signed_Sub_Slv_Sl = 343
+    Ieee_Std_Logic_Signed_Sub_Sl_Slv = 344
+    Ieee_Std_Logic_Arith_Conv_Unsigned_Int = 345
+    Ieee_Std_Logic_Arith_Conv_Unsigned_Uns = 346
+    Ieee_Std_Logic_Arith_Conv_Unsigned_Sgn = 347
+    Ieee_Std_Logic_Arith_Conv_Unsigned_Log = 348
+    Ieee_Std_Logic_Arith_Conv_Integer_Int = 349
+    Ieee_Std_Logic_Arith_Conv_Integer_Uns = 350
+    Ieee_Std_Logic_Arith_Conv_Integer_Sgn = 351
+    Ieee_Std_Logic_Arith_Conv_Integer_Log = 352
 
 Get_Kind = libghdl.vhdl__nodes__get_kind
 Get_Location = libghdl.vhdl__nodes__get_location
diff --git a/src/vhdl/translate/trans-chap7.adb b/src/vhdl/translate/trans-chap7.adb
index 58d63ce90..cf94655e3 100644
--- a/src/vhdl/translate/trans-chap7.adb
+++ b/src/vhdl/translate/trans-chap7.adb
@@ -6249,7 +6249,8 @@ package body Trans.Chap7 is
             null;
 
          when Iir_Predefined_Now_Function
-           | Iir_Predefined_Real_Now_Function =>
+           | Iir_Predefined_Real_Now_Function
+           | Iir_Predefined_Frequency_Function =>
             null;
 
             --  when others =>
diff --git a/src/vhdl/vhdl-evaluation.adb b/src/vhdl/vhdl-evaluation.adb
index 50e279a8f..5a4f2dde0 100644
--- a/src/vhdl/vhdl-evaluation.adb
+++ b/src/vhdl/vhdl-evaluation.adb
@@ -1726,6 +1726,7 @@ package body Vhdl.Evaluation is
            | Iir_Predefined_TF_Array_Not
            | Iir_Predefined_Now_Function
            | Iir_Predefined_Real_Now_Function
+           | Iir_Predefined_Frequency_Function
            | Iir_Predefined_Deallocate
            | Iir_Predefined_Write
            | Iir_Predefined_Read
diff --git a/src/vhdl/vhdl-nodes.ads b/src/vhdl/vhdl-nodes.ads
index 9a6e671e1..c59c1c046 100644
--- a/src/vhdl/vhdl-nodes.ads
+++ b/src/vhdl/vhdl-nodes.ads
@@ -5362,6 +5362,7 @@ package Vhdl.Nodes is
       --  Misc impure functions.
       Iir_Predefined_Now_Function,
       Iir_Predefined_Real_Now_Function,
+      Iir_Predefined_Frequency_Function,
 
       --  A not predefined and not known function.  User function.
       Iir_Predefined_None,
diff --git a/src/vhdl/vhdl-sem_stmts.adb b/src/vhdl/vhdl-sem_stmts.adb
index 98e01ccb3..43b41d16a 100644
--- a/src/vhdl/vhdl-sem_stmts.adb
+++ b/src/vhdl/vhdl-sem_stmts.adb
@@ -412,7 +412,7 @@ package body Vhdl.Sem_Stmts is
          when Iir_Kind_Free_Quantity_Declaration
            | Iir_Kinds_Branch_Quantity_Declaration
            | Iir_Kind_Dot_Attribute =>
-            if (Get_Kind (Get_Parent (Stmt))
+            if (Get_Kind (Get_Current_Concurrent_Statement)
                   /= Iir_Kind_Simultaneous_Procedural_Statement)
             then
                Error_Msg_Sem (+Stmt, "%n cannot be assigned", +Target_Prefix);
diff --git a/src/vhdl/vhdl-sem_types.adb b/src/vhdl/vhdl-sem_types.adb
index c02e682a8..3a0705d50 100644
--- a/src/vhdl/vhdl-sem_types.adb
+++ b/src/vhdl/vhdl-sem_types.adb
@@ -2400,11 +2400,13 @@ package body Vhdl.Sem_Types is
    --  Analyze NAME as a nature name.  Return NAME or an error node.
    function Sem_Nature_Mark (Name : Iir) return Iir
    is
-      Nature_Mark : Iir;
+      Nature_Mark : constant Iir := Sem_Denoting_Name (Name);
       Res : Iir;
    begin
-      Nature_Mark := Sem_Denoting_Name (Name);
       Res := Get_Named_Entity (Nature_Mark);
+      if Is_Error (Res) then
+         return Name;
+      end if;
       Res := Get_Nature (Res);
       case Get_Kind (Res) is
          when Iir_Kind_Scalar_Nature_Definition
diff --git a/src/vhdl/vhdl-std_package.adb b/src/vhdl/vhdl-std_package.adb
index d080327ff..7f6273dfe 100644
--- a/src/vhdl/vhdl-std_package.adb
+++ b/src/vhdl/vhdl-std_package.adb
@@ -1051,9 +1051,9 @@ package body Vhdl.Std_Package is
          Add_Decl (Function_Now);
       end;
 
-      --  AMS-LRM17 16.3
-      --  impure function NOW return REAL;
       if AMS_Vhdl then
+         --  AMS-LRM17 16.3
+         --  impure function NOW return REAL;
          declare
             Function_Now : Iir_Function_Declaration;
          begin
@@ -1066,6 +1066,21 @@ package body Vhdl.Std_Package is
             Vhdl.Sem_Utils.Compute_Subprogram_Hash (Function_Now);
             Add_Decl (Function_Now);
          end;
+
+         --  AMS-LRM17 16.3
+         --  impure function FREQUENCY return REAL;
+         declare
+            Function_Freq : Iir_Function_Declaration;
+         begin
+            Function_Freq := Create_Std_Decl (Iir_Kind_Function_Declaration);
+            Set_Std_Identifier (Function_Freq, Std_Names.Name_Frequency);
+            Set_Return_Type (Function_Freq, Real_Subtype_Definition);
+            Set_Pure_Flag (Function_Freq, False);
+            Set_Implicit_Definition
+              (Function_Freq, Iir_Predefined_Frequency_Function);
+            Vhdl.Sem_Utils.Compute_Subprogram_Hash (Function_Freq);
+            Add_Decl (Function_Freq);
+         end;
       end if;
 
       -- natural subtype