intel_alm: ABC9 sequential optimisations

5 files changed, 126 insertions, 10 deletions

diff --git a/techlibs/intel_alm/common/abc9_map.v b/techlibs/intel_alm/common/abc9_map.v
new file mode 100644
index 000000000..32ad79bdc
--- /dev/null
+++ b/techlibs/intel_alm/common/abc9_map.v
@@ -0,0 +1,18 @@
+// This file exists to map purely-synchronous flops to ABC9 flops, while 
+// mapping flops with asynchronous-clear as boxes, this is because ABC9 
+// doesn't support asynchronous-clear flops in sequential synthesis.
+
+module MISTRAL_FF(
+    input DATAIN, CLK, ACLR, ENA, SCLR, SLOAD, SDATA,
+    output reg Q
+);
+
+parameter _TECHMAP_CONSTMSK_ACLR_ = 1'b0;
+
+// If the async-clear is constant, we assume it's disabled.
+if (_TECHMAP_CONSTMSK_ACLR_ != 1'b0)
+    MISTRAL_FF_SYNCONLY _TECHMAP_REPLACE_ (.DATAIN(DATAIN), .CLK(CLK), .ENA(ENA), .SCLR(SCLR), .SLOAD(SLOAD), .SDATA(SDATA), .Q(Q));
+else
+    wire _TECHMAP_FAIL_ = 1;
+
+endmodule
diff --git a/techlibs/intel_alm/common/abc9_model.v b/techlibs/intel_alm/common/abc9_model.v
new file mode 100644
index 000000000..dd46147a5
--- /dev/null
+++ b/techlibs/intel_alm/common/abc9_model.v
@@ -0,0 +1,55 @@
+`ifdef cyclonev
+`define SYNCPATH 262
+`define SYNCSETUP 522
+`define COMBPATH 0
+`endif
+`ifdef cyclone10gx
+`define SYNCPATH 219
+`define SYNCSETUP 268
+`define COMBPATH 0
+`endif
+
+// fallback for when a family isn't detected (e.g. when techmapping for equivalence)
+`ifndef SYNCPATH
+`define SYNCPATH 0
+`define SYNCSETUP 0
+`define COMBPATH 0
+`endif
+
+// This is a purely-synchronous flop, that ABC9 can use for sequential synthesis.
+(* abc9_flop, lib_whitebox *)
+module MISTRAL_FF_SYNCONLY(
+    input DATAIN, CLK, ENA, SCLR, SLOAD, SDATA,
+    output reg Q
+);
+
+specify
+    if (ENA) (posedge CLK => (Q : DATAIN)) = `SYNCPATH;
+    if (ENA) (posedge CLK => (Q : SCLR)) = `SYNCPATH;
+    if (ENA) (posedge CLK => (Q : SLOAD)) = `SYNCPATH;
+    if (ENA) (posedge CLK => (Q : SDATA)) = `SYNCPATH;
+
+    $setup(DATAIN, posedge CLK, `SYNCSETUP);
+    $setup(ENA, posedge CLK, `SYNCSETUP);
+    $setup(SCLR, posedge CLK, `SYNCSETUP);
+    $setup(SLOAD, posedge CLK, `SYNCSETUP);
+    $setup(SDATA, posedge CLK, `SYNCSETUP);
+endspecify
+
+initial begin
+    // Altera flops initialise to zero.
+	Q = 0;
+end
+
+always @(posedge CLK) begin
+    // Clock-enable
+	if (ENA) begin
+        // Synchronous clear
+        if (SCLR) Q <= 0;
+        // Synchronous load
+        else if (SLOAD) Q <= SDATA;
+        else Q <= DATAIN;
+    end
+end
+
+endmodule
diff --git a/techlibs/intel_alm/common/abc9_unmap.v b/techlibs/intel_alm/common/abc9_unmap.v
new file mode 100644
index 000000000..0eda69560
--- /dev/null
+++ b/techlibs/intel_alm/common/abc9_unmap.v
@@ -0,0 +1,11 @@
+// After performing sequential synthesis, map the synchronous flops back to
+// standard MISTRAL_FF flops.
+
+module MISTRAL_FF_SYNCONLY(
+    input DATAIN, CLK, ENA, SCLR, SLOAD, SDATA,
+    output reg Q
+);
+
+MISTRAL_FF _TECHMAP_REPLACE_ (.DATAIN(DATAIN), .CLK(CLK), .ACLR(1'b1), .ENA(ENA), .SCLR(SCLR), .SLOAD(SLOAD), .SDATA(SDATA), .Q(Q));
+
+endmodule
diff --git a/techlibs/intel_alm/common/dff_sim.v b/techlibs/intel_alm/common/dff_sim.v
index 32444dd46..94aa37fb5 100644
--- a/techlibs/intel_alm/common/dff_sim.v
+++ b/techlibs/intel_alm/common/dff_sim.v
@@ -53,23 +53,45 @@
 // Q: data output
 //
 // Note: the DFFEAS primitive is mostly emulated; it does not reflect what the hardware implements.
+
+`ifdef cyclonev
+`define SYNCPATH 262
+`define SYNCSETUP 522
+`define COMBPATH 0
+`endif
+`ifdef cyclone10gx
+`define SYNCPATH 219
+`define SYNCSETUP 268
+`define COMBPATH 0
+`endif
+
+// fallback for when a family isn't detected (e.g. when techmapping for equivalence)
+`ifndef SYNCPATH
+`define SYNCPATH 0
+`define SYNCSETUP 0
+`define COMBPATH 0
+`endif
+
+(* abc9_box, lib_whitebox *)
 module MISTRAL_FF(
     input DATAIN, CLK, ACLR, ENA, SCLR, SLOAD, SDATA,
     output reg Q
 );
 
-`ifdef cyclonev
-specify
-    (posedge CLK => (Q : DATAIN)) = 262;
-    $setup(DATAIN, posedge CLK, 522);
-endspecify
-`endif
-`ifdef cyclone10gx
 specify
-    (posedge CLK => (Q : DATAIN)) = 219;
-    $setup(DATAIN, posedge CLK, 268);
+    if (ENA) (posedge CLK => (Q : DATAIN)) = `SYNCPATH;
+    if (ENA) (posedge CLK => (Q : SCLR)) = `SYNCPATH;
+    if (ENA) (posedge CLK => (Q : SLOAD)) = `SYNCPATH;
+    if (ENA) (posedge CLK => (Q : SDATA)) = `SYNCPATH;
+
+    $setup(DATAIN, posedge CLK, `SYNCSETUP);
+    $setup(ENA, posedge CLK, `SYNCSETUP);
+    $setup(SCLR, posedge CLK, `SYNCSETUP);
+    $setup(SLOAD, posedge CLK, `SYNCSETUP);
+    $setup(SDATA, posedge CLK, `SYNCSETUP);
+
+    (ACLR => Q) = `COMBPATH;
 endspecify
-`endif
 
 initial begin
     // Altera flops initialise to zero.
diff --git a/techlibs/intel_alm/common/mem_sim.v b/techlibs/intel_alm/common/mem_sim.v
index ae79b19a4..f6f9ecb02 100644
--- a/techlibs/intel_alm/common/mem_sim.v
+++ b/techlibs/intel_alm/common/mem_sim.v
@@ -48,10 +48,20 @@
 // the following model because it's very difficult to trigger this in practice
 // as clock cycles will be much longer than any potential blip of 'x, so the
 // model can be treated as always returning a defined result.
+
+(* abc9_box, lib_whitebox *)
 module MISTRAL_MLAB(input [4:0] A1ADDR, input A1DATA, A1EN, CLK1, input [4:0] B1ADDR, output B1DATA);
 
 reg [31:0] mem = 32'b0;
 
+// TODO
+specify
+    $setup(A1ADDR, posedge CLK1, 0);
+    $setup(A1DATA, posedge CLK1, 0);
+
+    (B1ADDR *> B1DATA) = 0;
+endspecify
+
 always @(posedge CLK1)
     if (A1EN) mem[A1ADDR] <= A1DATA;