Remove the glitch observed on dtack in MBLT mode (seen on Dab64x at 40MHz with MEN-A20).

61d6769b · Mathieu Saccani · def8d371 · 61d6769b
Commit 61d6769b authored Dec 07, 2020 by Mathieu Saccani
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vme_bus.vhd hdl/rtl/vme_bus.vhd +8 -0

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--- a/hdl/rtl/vme_bus.vhd
+++ b/hdl/rtl/vme_bus.vhd
@@ -708,9 +708,17 @@ begin

                --  Keep same direction for data and address.
                s_mainFSMstate <= WAIT_FOR_DS;
+                
+                --  Early drive for MBLT.
+                vme_dtack_async_ctrl <= '0';
              end if;
            else
              s_mainFSMstate <= DTACK_LOW;
+              
+              --  Early drive for MBLT.
+              if s_irq_sel='0' and g_VME32 and s_transferType = MBLT then
+                vme_dtack_async_ctrl <= '0';
+              end if;
            end if;

          when APHASE_2 =>