mirror of https://github.com/YosysHQ/yosys.git
Update comments in abc9_map.v
This commit is contained in:
parent
1dc22607c3
commit
bae3d8705d
|
@ -28,12 +28,53 @@
|
||||||
|
|
||||||
// ============================================================================
|
// ============================================================================
|
||||||
|
|
||||||
// The purpose of the following FD* rules are to wrap the flop (which, when
|
// `abc9' requires that complex flops be split into a combinatorial box
|
||||||
// called with the `_ABC' macro set captures only its combinatorial
|
// feeding a simple flop ($_ABC9_FF_).
|
||||||
// behaviour) with:
|
// Yosys will automatically analyse the simulation model (described in
|
||||||
|
// cells_sim.v) and detach any $_DFF_P_ or $_DFF_N_ cells present in
|
||||||
|
// order to extract the combinatorial control logic left behind.
|
||||||
|
// Specifically, a simulation model similar to the one below:
|
||||||
|
//
|
||||||
|
// ++===================================++
|
||||||
|
// || Sim model ||
|
||||||
|
// || /\/\/\/\ ||
|
||||||
|
// D -->>-----< > +------+ ||
|
||||||
|
// R -->>-----< Comb. > |$_DFF_| ||
|
||||||
|
// CE -->>-----< logic >-----| [NP]_|---+---->>-- Q
|
||||||
|
// || +--< > +------+ | ||
|
||||||
|
// || | \/\/\/\/ | ||
|
||||||
|
// || | | ||
|
||||||
|
// || +----------------------------+ ||
|
||||||
|
// || ||
|
||||||
|
// ++===================================++
|
||||||
|
//
|
||||||
|
// is transformed into:
|
||||||
|
//
|
||||||
|
// ++==================++
|
||||||
|
// || Comb box ||
|
||||||
|
// || ||
|
||||||
|
// || /\/\/\/\ ||
|
||||||
|
// D -->>-----< > || +------+
|
||||||
|
// R -->>-----< Comb. > || |$_ABC_|
|
||||||
|
// CE -->>-----< logic >--->>-- $nextQ --| FF_ |--+-->> Q
|
||||||
|
// $currQ +-->>-----< > || +------+ |
|
||||||
|
// | || \/\/\/\/ || |
|
||||||
|
// | || || |
|
||||||
|
// | ++==================++ |
|
||||||
|
// | |
|
||||||
|
// +----------------------------------------------+
|
||||||
|
//
|
||||||
|
// The purpose of the following FD* rules are to wrap the flop with:
|
||||||
// (a) a special $__ABC9_FF_ in front of the FD*'s output, indicating to abc9
|
// (a) a special $__ABC9_FF_ in front of the FD*'s output, indicating to abc9
|
||||||
// the connectivity of its basic D-Q flop
|
// the connectivity of its basic D-Q flop
|
||||||
// (b) a special TECHMAP_REPLACE_.$currQ wire that will be used for feedback
|
// (b) a special _TECHMAP_REPLACE_.$abc9_clock wire to capture its clock
|
||||||
|
// domain (used when partitioning the module so that `abc9' only
|
||||||
|
// performs sequential synthesis (with reachability analysis) correctly on
|
||||||
|
// one domain at a time)
|
||||||
|
// (c) a special _TECHMAP_REPLACE_.$abc9_control that captures the control
|
||||||
|
// domain (which, combined with this cell type, encodes to `abc9' which
|
||||||
|
// flops may be merged together)
|
||||||
|
// (d) a special _TECHMAP_REPLACE_.$currQ wire that will be used for feedback
|
||||||
// into the (combinatorial) FD* cell to facilitate clock-enable behaviour
|
// into the (combinatorial) FD* cell to facilitate clock-enable behaviour
|
||||||
module FDRE (output reg Q, input C, CE, D, R);
|
module FDRE (output reg Q, input C, CE, D, R);
|
||||||
parameter [0:0] INIT = 1'b0;
|
parameter [0:0] INIT = 1'b0;
|
||||||
|
@ -49,56 +90,11 @@ module FDRE (output reg Q, input C, CE, D, R);
|
||||||
) _TECHMAP_REPLACE_ (
|
) _TECHMAP_REPLACE_ (
|
||||||
.D(D), .Q($nextQ), .C(C), .CE(CE), .R(R)
|
.D(D), .Q($nextQ), .C(C), .CE(CE), .R(R)
|
||||||
);
|
);
|
||||||
// `abc9' requires that complex flops be split into a combinatorial box
|
|
||||||
// feeding a simple flop ($_ABC9_FF_).
|
|
||||||
// Yosys will automatically analyse the simulation model (described in
|
|
||||||
// cells_sim.v) and detach any $_DFF_P_ or $_DFF_N_ cells present in
|
|
||||||
// order to extract the combinatorial control logic left behind.
|
|
||||||
// Specifically, a simulation model similar to the one below:
|
|
||||||
//
|
|
||||||
// ++===================================++
|
|
||||||
// || Sim model ||
|
|
||||||
// || /\/\/\/\ ||
|
|
||||||
// D -->>-----< > +------+ ||
|
|
||||||
// R -->>-----< Comb. > |$_DFF_| ||
|
|
||||||
// CE -->>-----< logic >-----| [NP]_|---+---->>-- Q
|
|
||||||
// || +--< > +------+ | ||
|
|
||||||
// || | \/\/\/\/ | ||
|
|
||||||
// || | | ||
|
|
||||||
// || +----------------------------+ ||
|
|
||||||
// || ||
|
|
||||||
// ++===================================++
|
|
||||||
//
|
|
||||||
// is transformed into:
|
|
||||||
//
|
|
||||||
// ++==================++
|
|
||||||
// || Comb box ||
|
|
||||||
// || ||
|
|
||||||
// || /\/\/\/\ ||
|
|
||||||
// D -->>-----< > || +------+
|
|
||||||
// R -->>-----< Comb. > || |$_ABC_|
|
|
||||||
// CE -->>-----< logic >--->>-- $nextQ --| FF_ |--+-->> Q
|
|
||||||
// $currQ +-->>-----< > || +------+ |
|
|
||||||
// | || \/\/\/\/ || |
|
|
||||||
// | || || |
|
|
||||||
// | ++==================++ |
|
|
||||||
// | |
|
|
||||||
// +----------------------------------------------+
|
|
||||||
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q(Q));
|
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q(Q));
|
||||||
|
|
||||||
// Special signal indicating clock domain
|
// Special signals
|
||||||
// (used to partition the module so that `abc9' only performs
|
|
||||||
// sequential synthesis (reachability analysis) correctly on
|
|
||||||
// one domain at a time)
|
|
||||||
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, IS_C_INVERTED};
|
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, IS_C_INVERTED};
|
||||||
// Special signal indicating control domain
|
|
||||||
// (which, combined with this cell type, encodes to `abc9'
|
|
||||||
// which flops may be merged together)
|
|
||||||
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, IS_D_INVERTED, R, IS_R_INVERTED};
|
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, IS_D_INVERTED, R, IS_R_INVERTED};
|
||||||
// Special signal indicating the current value of the flip-flop
|
|
||||||
// In order to achieve clock-enable behaviour, the current value
|
|
||||||
// of the sequential output is required which Yosys will
|
|
||||||
// connect to the special `$currQ' wire.
|
|
||||||
wire _TECHMAP_REPLACE_.$currQ = Q;
|
wire _TECHMAP_REPLACE_.$currQ = Q;
|
||||||
endmodule
|
endmodule
|
||||||
module FDRE_1 (output reg Q, input C, CE, D, R);
|
module FDRE_1 (output reg Q, input C, CE, D, R);
|
||||||
|
@ -111,19 +107,9 @@ module FDRE_1 (output reg Q, input C, CE, D, R);
|
||||||
);
|
);
|
||||||
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q(Q));
|
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q(Q));
|
||||||
|
|
||||||
// Special signal indicating clock domain
|
// Special signals
|
||||||
// (used to partition the module so that `abc9' only performs
|
|
||||||
// sequential synthesis (reachability analysis) correctly on
|
|
||||||
// one domain at a time)
|
|
||||||
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, 1'b1 /* IS_C_INVERTED */};
|
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, 1'b1 /* IS_C_INVERTED */};
|
||||||
// Special signal indicating control domain
|
|
||||||
// (which, combined with this spell type, encodes to `abc9'
|
|
||||||
// which flops may be merged together)
|
|
||||||
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, 1'b0 /* IS_D_INVERTED */, R, 1'b0 /* IS_R_INVERTED */};
|
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, 1'b0 /* IS_D_INVERTED */, R, 1'b0 /* IS_R_INVERTED */};
|
||||||
// Special signal indicating the current value of the flip-flop
|
|
||||||
// In order to achieve clock-enable behaviour, the current value
|
|
||||||
// of the sequential output is required which Yosys will
|
|
||||||
// connect to the special `$currQ' wire.
|
|
||||||
wire _TECHMAP_REPLACE_.$currQ = Q;
|
wire _TECHMAP_REPLACE_.$currQ = Q;
|
||||||
endmodule
|
endmodule
|
||||||
|
|
||||||
|
@ -142,7 +128,7 @@ module FDCE (output reg Q, input C, CE, D, CLR);
|
||||||
.D(D), .Q($nextQ), .C(C), .CE(CE), .CLR(IS_CLR_INVERTED)
|
.D(D), .Q($nextQ), .C(C), .CE(CE), .CLR(IS_CLR_INVERTED)
|
||||||
// ^^^ Note that async
|
// ^^^ Note that async
|
||||||
// control is disabled
|
// control is disabled
|
||||||
// and captured by
|
// here but captured by
|
||||||
// $__ABC9_ASYNC below
|
// $__ABC9_ASYNC below
|
||||||
);
|
);
|
||||||
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q($currQ));
|
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q($currQ));
|
||||||
|
@ -150,19 +136,9 @@ module FDCE (output reg Q, input C, CE, D, CLR);
|
||||||
// using the $_ABC9_ASYNC box by abc9_map.v
|
// using the $_ABC9_ASYNC box by abc9_map.v
|
||||||
\$__ABC9_ASYNC abc_async (.A($currQ), .S(CLR ^ IS_CLR_INVERTED), .Y(Q));
|
\$__ABC9_ASYNC abc_async (.A($currQ), .S(CLR ^ IS_CLR_INVERTED), .Y(Q));
|
||||||
|
|
||||||
// Special signal indicating clock domain
|
// Special signals
|
||||||
// (used to partition the module so that `abc9' only performs
|
|
||||||
// sequential synthesis (reachability analysis) correctly on
|
|
||||||
// one domain at a time)
|
|
||||||
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, IS_C_INVERTED};
|
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, IS_C_INVERTED};
|
||||||
// Special signal indicating control domain
|
|
||||||
// (which, combined with this spell type, encodes to `abc9'
|
|
||||||
// which flops may be merged together)
|
|
||||||
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, IS_D_INVERTED, CLR, IS_CLR_INVERTED};
|
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, IS_D_INVERTED, CLR, IS_CLR_INVERTED};
|
||||||
// Special signal indicating the current value of the flip-flop
|
|
||||||
// In order to achieve clock-enable behaviour, the current value
|
|
||||||
// of the sequential output is required which Yosys will
|
|
||||||
// connect to the special `$currQ' wire.
|
|
||||||
wire _TECHMAP_REPLACE_.$currQ = $currQ;
|
wire _TECHMAP_REPLACE_.$currQ = $currQ;
|
||||||
endmodule
|
endmodule
|
||||||
module FDCE_1 (output reg Q, input C, CE, D, CLR);
|
module FDCE_1 (output reg Q, input C, CE, D, CLR);
|
||||||
|
@ -174,25 +150,15 @@ module FDCE_1 (output reg Q, input C, CE, D, CLR);
|
||||||
.D(D), .Q($nextQ), .C(C), .CE(CE), .CLR(1'b0)
|
.D(D), .Q($nextQ), .C(C), .CE(CE), .CLR(1'b0)
|
||||||
// ^^^ Note that async
|
// ^^^ Note that async
|
||||||
// control is disabled
|
// control is disabled
|
||||||
// and captured by
|
// here but captured by
|
||||||
// $__ABC9_ASYNC below
|
// $__ABC9_ASYNC below
|
||||||
);
|
);
|
||||||
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q($currQ));
|
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q($currQ));
|
||||||
\$__ABC9_ASYNC abc_async (.A($currQ), .S(CLR), .Y(Q));
|
\$__ABC9_ASYNC abc_async (.A($currQ), .S(CLR), .Y(Q));
|
||||||
|
|
||||||
// Special signal indicating clock domain
|
// Special signals
|
||||||
// (used to partition the module so that `abc9' only performs
|
|
||||||
// sequential synthesis (reachability analysis) correctly on
|
|
||||||
// one domain at a time)
|
|
||||||
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, 1'b1 /* IS_C_INVERTED */};
|
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, 1'b1 /* IS_C_INVERTED */};
|
||||||
// Special signal indicating control domain
|
|
||||||
// (which, combined with this spell type, encodes to `abc9'
|
|
||||||
// which flops may be merged together)
|
|
||||||
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, 1'b0 /* IS_D_INVERTED */, CLR, 1'b0 /* IS_CLR_INVERTED */};
|
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, 1'b0 /* IS_D_INVERTED */, CLR, 1'b0 /* IS_CLR_INVERTED */};
|
||||||
// Special signal indicating the current value of the flip-flop
|
|
||||||
// In order to achieve clock-enable behaviour, the current value
|
|
||||||
// of the sequential output is required which Yosys will
|
|
||||||
// connect to the special `$currQ' wire.
|
|
||||||
wire _TECHMAP_REPLACE_.$currQ = $currQ;
|
wire _TECHMAP_REPLACE_.$currQ = $currQ;
|
||||||
endmodule
|
endmodule
|
||||||
|
|
||||||
|
@ -211,25 +177,15 @@ module FDPE (output reg Q, input C, CE, D, PRE);
|
||||||
.D(D), .Q($nextQ), .C(C), .CE(CE), .PRE(IS_PRE_INVERTED)
|
.D(D), .Q($nextQ), .C(C), .CE(CE), .PRE(IS_PRE_INVERTED)
|
||||||
// ^^^ Note that async
|
// ^^^ Note that async
|
||||||
// control is disabled
|
// control is disabled
|
||||||
// and captured by
|
// here but captured by
|
||||||
// $__ABC9_ASYNC below
|
// $__ABC9_ASYNC below
|
||||||
);
|
);
|
||||||
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q($currQ));
|
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q($currQ));
|
||||||
\$__ABC9_ASYNC abc_async (.A($currQ), .S(PRE ^ IS_PRE_INVERTED), .Y(Q));
|
\$__ABC9_ASYNC abc_async (.A($currQ), .S(PRE ^ IS_PRE_INVERTED), .Y(Q));
|
||||||
|
|
||||||
// Special signal indicating clock domain
|
// Special signals
|
||||||
// (used to partition the module so that `abc9' only performs
|
|
||||||
// sequential synthesis (reachability analysis) correctly on
|
|
||||||
// one domain at a time)
|
|
||||||
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, IS_C_INVERTED};
|
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, IS_C_INVERTED};
|
||||||
// Special signal indicating control domain
|
|
||||||
// (which, combined with this spell type, encodes to `abc9'
|
|
||||||
// which flops may be merged together)
|
|
||||||
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, IS_D_INVERTED, PRE, IS_PRE_INVERTED};
|
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, IS_D_INVERTED, PRE, IS_PRE_INVERTED};
|
||||||
// Special signal indicating the current value of the flip-flop
|
|
||||||
// In order to achieve clock-enable behaviour, the current value
|
|
||||||
// of the sequential output is required which Yosys will
|
|
||||||
// connect to the special `$currQ' wire.
|
|
||||||
wire _TECHMAP_REPLACE_.$currQ = $currQ;
|
wire _TECHMAP_REPLACE_.$currQ = $currQ;
|
||||||
endmodule
|
endmodule
|
||||||
module FDPE_1 (output reg Q, input C, CE, D, PRE);
|
module FDPE_1 (output reg Q, input C, CE, D, PRE);
|
||||||
|
@ -241,25 +197,15 @@ module FDPE_1 (output reg Q, input C, CE, D, PRE);
|
||||||
.D(D), .Q($nextQ), .C(C), .CE(CE), .PRE(1'b0)
|
.D(D), .Q($nextQ), .C(C), .CE(CE), .PRE(1'b0)
|
||||||
// ^^^ Note that async
|
// ^^^ Note that async
|
||||||
// control is disabled
|
// control is disabled
|
||||||
// and captured by
|
// here but captured by
|
||||||
// $__ABC9_ASYNC below
|
// $__ABC9_ASYNC below
|
||||||
);
|
);
|
||||||
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q($currQ));
|
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q($currQ));
|
||||||
\$__ABC9_ASYNC abc_async (.A($currQ), .S(PRE), .Y(Q));
|
\$__ABC9_ASYNC abc_async (.A($currQ), .S(PRE), .Y(Q));
|
||||||
|
|
||||||
// Special signal indicating clock domain
|
// Special signals
|
||||||
// (used to partition the module so that `abc9' only performs
|
|
||||||
// sequential synthesis (reachability analysis) correctly on
|
|
||||||
// one domain at a time)
|
|
||||||
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, 1'b1 /* IS_C_INVERTED */};
|
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, 1'b1 /* IS_C_INVERTED */};
|
||||||
// Special signal indicating control domain
|
|
||||||
// (which, combined with this spell type, encodes to `abc9'
|
|
||||||
// which flops may be merged together)
|
|
||||||
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, 1'b0 /* IS_D_INVERTED */, PRE, 1'b0 /* IS_PRE_INVERTED */};
|
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, 1'b0 /* IS_D_INVERTED */, PRE, 1'b0 /* IS_PRE_INVERTED */};
|
||||||
// Special signal indicating the current value of the flip-flop
|
|
||||||
// In order to achieve clock-enable behaviour, the current value
|
|
||||||
// of the sequential output is required which Yosys will
|
|
||||||
// connect to the special `$currQ' wire.
|
|
||||||
wire _TECHMAP_REPLACE_.$currQ = $currQ;
|
wire _TECHMAP_REPLACE_.$currQ = $currQ;
|
||||||
endmodule
|
endmodule
|
||||||
|
|
||||||
|
@ -279,19 +225,9 @@ module FDSE (output reg Q, input C, CE, D, S);
|
||||||
);
|
);
|
||||||
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q(Q));
|
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q(Q));
|
||||||
|
|
||||||
// Special signal indicating clock domain
|
// Special signals
|
||||||
// (used to partition the module so that `abc9' only performs
|
|
||||||
// sequential synthesis (reachability analysis) correctly on
|
|
||||||
// one domain at a time)
|
|
||||||
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, IS_C_INVERTED};
|
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, IS_C_INVERTED};
|
||||||
// Special signal indicating control domain
|
|
||||||
// (which, combined with this spell type, encodes to `abc9'
|
|
||||||
// which flops may be merged together)
|
|
||||||
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, IS_D_INVERTED, S, IS_S_INVERTED};
|
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, IS_D_INVERTED, S, IS_S_INVERTED};
|
||||||
// Special signal indicating the current value of the flip-flop
|
|
||||||
// In order to achieve clock-enable behaviour, the current value
|
|
||||||
// of the sequential output is required which Yosys will
|
|
||||||
// connect to the special `$currQ' wire.
|
|
||||||
wire _TECHMAP_REPLACE_.$currQ = Q;
|
wire _TECHMAP_REPLACE_.$currQ = Q;
|
||||||
endmodule
|
endmodule
|
||||||
module FDSE_1 (output reg Q, input C, CE, D, S);
|
module FDSE_1 (output reg Q, input C, CE, D, S);
|
||||||
|
@ -304,19 +240,9 @@ module FDSE_1 (output reg Q, input C, CE, D, S);
|
||||||
);
|
);
|
||||||
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q(Q));
|
\$__ABC9_FF_ abc_dff (.D($nextQ), .Q(Q));
|
||||||
|
|
||||||
// Special signal indicating clock domain
|
// Special signals
|
||||||
// (used to partition the module so that `abc9' only performs
|
|
||||||
// sequential synthesis (reachability analysis) correctly on
|
|
||||||
// one domain at a time)
|
|
||||||
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, 1'b1 /* IS_C_INVERTED */};
|
wire [1:0] _TECHMAP_REPLACE_.$abc9_clock = {C, 1'b1 /* IS_C_INVERTED */};
|
||||||
// Special signal indicating control domain
|
|
||||||
// (which, combined with this spell type, encodes to `abc9'
|
|
||||||
// which flops may be merged together)
|
|
||||||
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, 1'b0 /* IS_D_INVERTED */, S, 1'b0 /* IS_S_INVERTED */};
|
wire [3:0] _TECHMAP_REPLACE_.$abc9_control = {CE, 1'b0 /* IS_D_INVERTED */, S, 1'b0 /* IS_S_INVERTED */};
|
||||||
// Special signal indicating the current value of the flip-flop
|
|
||||||
// In order to achieve clock-enable behaviour, the current value
|
|
||||||
// of the sequential output is required which Yosys will
|
|
||||||
// connect to the special `$currQ' wire.
|
|
||||||
wire _TECHMAP_REPLACE_.$currQ = Q;
|
wire _TECHMAP_REPLACE_.$currQ = Q;
|
||||||
endmodule
|
endmodule
|
||||||
|
|
||||||
|
|
Loading…
Reference in New Issue