From 71da8363008159fed399ec74318d83e34642d1f2 Mon Sep 17 00:00:00 2001 From: Luke Wren Date: Wed, 17 Apr 2019 22:56:41 +0100 Subject: [PATCH] ice40 cells_sim.v: SB_IO: update clock enable behaviour based on hardware experiments --- techlibs/ice40/cells_sim.v | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-) diff --git a/techlibs/ice40/cells_sim.v b/techlibs/ice40/cells_sim.v index 62a28364b..00843b97c 100644 --- a/techlibs/ice40/cells_sim.v +++ b/techlibs/ice40/cells_sim.v @@ -27,18 +27,27 @@ module SB_IO ( reg dout_q_0, dout_q_1; reg outena_q; + // IO tile generates a constant 1'b1 internally if global_cen is not connected + wire clken_pulled = CLOCK_ENABLE || CLOCK_ENABLE === 1'bz; + reg clken_pulled_ri; + reg clken_pulled_ro; + generate if (!NEG_TRIGGER) begin - always @(posedge INPUT_CLK) if (CLOCK_ENABLE) din_q_0 <= PACKAGE_PIN; - always @(negedge INPUT_CLK) if (CLOCK_ENABLE) din_q_1 <= PACKAGE_PIN; - always @(posedge OUTPUT_CLK) if (CLOCK_ENABLE) dout_q_0 <= D_OUT_0; - always @(negedge OUTPUT_CLK) if (CLOCK_ENABLE) dout_q_1 <= D_OUT_1; - always @(posedge OUTPUT_CLK) if (CLOCK_ENABLE) outena_q <= OUTPUT_ENABLE; + always @(posedge INPUT_CLK) clken_pulled_ri <= clken_pulled; + always @(posedge INPUT_CLK) if (clken_pulled) din_q_0 <= PACKAGE_PIN; + always @(negedge INPUT_CLK) if (clken_pulled_ri) din_q_1 <= PACKAGE_PIN; + always @(posedge OUTPUT_CLK) clken_pulled_ro <= clken_pulled; + always @(posedge OUTPUT_CLK) if (clken_pulled) dout_q_0 <= D_OUT_0; + always @(negedge OUTPUT_CLK) if (clken_pulled_ro) dout_q_1 <= D_OUT_1; + always @(posedge OUTPUT_CLK) if (clken_pulled) outena_q <= OUTPUT_ENABLE; end else begin - always @(negedge INPUT_CLK) if (CLOCK_ENABLE) din_q_0 <= PACKAGE_PIN; - always @(posedge INPUT_CLK) if (CLOCK_ENABLE) din_q_1 <= PACKAGE_PIN; - always @(negedge OUTPUT_CLK) if (CLOCK_ENABLE) dout_q_0 <= D_OUT_0; - always @(posedge OUTPUT_CLK) if (CLOCK_ENABLE) dout_q_1 <= D_OUT_1; - always @(negedge OUTPUT_CLK) if (CLOCK_ENABLE) outena_q <= OUTPUT_ENABLE; + always @(negedge INPUT_CLK) clken_pulled_ri <= clken_pulled; + always @(negedge INPUT_CLK) if (clken_pulled) din_q_0 <= PACKAGE_PIN; + always @(posedge INPUT_CLK) if (clken_pulled_ri) din_q_1 <= PACKAGE_PIN; + always @(negedge OUTPUT_CLK) clken_pulled_ro <= clken_pulled; + always @(negedge OUTPUT_CLK) if (clken_pulled) dout_q_0 <= D_OUT_0; + always @(posedge OUTPUT_CLK) if (clken_pulled_ro) dout_q_1 <= D_OUT_1; + always @(negedge OUTPUT_CLK) if (clken_pulled) outena_q <= OUTPUT_ENABLE; end endgenerate always @* begin -- 2.30.2