Disable support for SB_MAC16 reset since it is async

diff --git a/passes/pmgen/ice40_dsp.cc b/passes/pmgen/ice40_dsp.cc
index 2d264a6d1633844235526445d37e629044f3eb66..cff4c5ddb577f23e54ab2c84a783b28b652e1420 100644 (file)
--- a/passes/pmgen/ice40_dsp.cc
+++ b/passes/pmgen/ice40_dsp.cc
@@ -287,9 +287,9 @@ struct Ice40DspPass : public Pass {
                log("cells into iCE40 DSP resources.\n");
                log("Currently, only the 16x16 multiply mode is supported and not the 2 x 8x8 mode.\n");
                log("\n");
-               log("Pack input registers (A, B, {C,D}; with optional hold/reset), pipeline registers\n");
-               log("({F,J,K,G}, H; with shared reset), output registers (O; with optional hold/reset),\n");
-               log("and post-adder into the SB_MAC16 resource.\n");
+               log("Pack input registers (A, B, {C,D}; with optional hold), pipeline registers\n");
+               log("({F,J,K,G}, H), output registers (O; with optional hold), and post-adder into\n");
+               log("into the SB_MAC16 resource.\n");
                log("\n");
                log("Multiply-accumulate operations using the post-adder with feedback on the {C,D}\n");
                log("input will be folded into the DSP. In this scenario only, resetting the\n");

diff --git a/passes/pmgen/ice40_dsp.pmg b/passes/pmgen/ice40_dsp.pmg
index 09fd8406db72efff893d58dad36027ef776f68a8..b4bfdce4ab864375c11fe4c68f77846c23a45fcc 100644 (file)
--- a/passes/pmgen/ice40_dsp.pmg
+++ b/passes/pmgen/ice40_dsp.pmg
@@ -384,6 +384,8 @@ code argQ argD
 endcode
 
 match ffrstmux
+       if false /* TODO: ice40 resets are actually async */
+
        if !argD.empty()
        select ffrstmux->type.in($mux)
        index <SigSpec> port(ffrstmux, \Y) === argD
@@ -487,6 +489,8 @@ code argD argQ
 endcode
 
 match ffrstmux
+       if false /* TODO: ice40 resets are actually async */
+
        select ffrstmux->type.in($mux)
        // ffrstmux output must have two users: ffrstmux and ff.D
        select nusers(port(ffrstmux, \Y)) == 2