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xilinx: Improve flip-flop handling.

This adds support for infering more kinds of flip-flops:

- FFs with async set/reset and clock enable
- FFs with sync set/reset
- FFs with sync set/reset and clock enable

Some passes have been moved (and some added) in order for dff2dffs to
work correctly.

This gives us complete coverage of Virtex 6+ and Spartan 6 flip-flop
capabilities (though not latch capabilities).  Older FPGAs also support
having both a set and a reset input, which will be handled at a later
data.
This commit is contained in:
Marcin Kościelnicki 2019-11-21 06:30:06 +01:00 committed by Marcin Kościelnicki
parent 22dd9f107c
commit aff6ad1ce0
8 changed files with 264 additions and 71 deletions

View file

@ -28,6 +28,33 @@ module _90_dff_nn1_to_np1 (input D, C, R, output Q); \$_DFF_NP1_ _TECHMAP_REPL
(* techmap_celltype = "$_DFF_PN1_" *)
module _90_dff_pn1_to_pp1 (input D, C, R, output Q); \$_DFF_PP1_ _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R)); endmodule
(* techmap_celltype = "$__DFFE_NN0" *)
module _90_dffe_nn0_to_np0 (input D, C, R, E, output Q); \$__DFFE_NP0 _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R), .E(E)); endmodule
(* techmap_celltype = "$__DFFE_PN0" *)
module _90_dffe_pn0_to_pp0 (input D, C, R, E, output Q); \$__DFFE_PP0 _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R), .E(E)); endmodule
(* techmap_celltype = "$__DFFE_NN1" *)
module _90_dffe_nn1_to_np1 (input D, C, R, E, output Q); \$__DFFE_NP1 _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R), .E(E)); endmodule
(* techmap_celltype = "$__DFFE_PN1" *)
module _90_dffe_pn1_to_pp1 (input D, C, R, E, output Q); \$__DFFE_PP1 _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R), .E(E)); endmodule
(* techmap_celltype = "$__DFFS_NN0_" *)
module _90_dffs_nn0_to_np0 (input D, C, R, output Q); \$__DFFS_NP0_ _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R)); endmodule
(* techmap_celltype = "$__DFFS_PN0_" *)
module _90_dffs_pn0_to_pp0 (input D, C, R, output Q); \$__DFFS_PP0_ _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R)); endmodule
(* techmap_celltype = "$__DFFS_NN1_" *)
module _90_dffs_nn1_to_np1 (input D, C, R, output Q); \$__DFFS_NP1_ _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R)); endmodule
(* techmap_celltype = "$__DFFS_PN1_" *)
module _90_dffs_pn1_to_pp1 (input D, C, R, output Q); \$__DFFS_PP1_ _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R)); endmodule
(* techmap_celltype = "$__DFFSE_NN0" *)
module _90_dffse_nn0_to_np0 (input D, C, R, E, output Q); \$__DFFSE_NP0 _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R), .E(E)); endmodule
(* techmap_celltype = "$__DFFSE_PN0" *)
module _90_dffse_pn0_to_pp0 (input D, C, R, E, output Q); \$__DFFSE_PP0 _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R), .E(E)); endmodule
(* techmap_celltype = "$__DFFSE_NN1" *)
module _90_dffse_nn1_to_np1 (input D, C, R, E, output Q); \$__DFFSE_NP1 _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R), .E(E)); endmodule
(* techmap_celltype = "$__DFFSE_PN1" *)
module _90_dffse_pn1_to_pp1 (input D, C, R, E, output Q); \$__DFFSE_PP1 _TECHMAP_REPLACE_ (.D(D), .Q(Q), .C(C), .R(~R), .E(E)); endmodule
module \$__SHREG_ (input C, input D, input E, output Q);
parameter DEPTH = 0;
parameter [DEPTH-1:0] INIT = 0;