Add some flops to the mapper

This is NOT how to do CDC

hw/efinix_fpga/src/mapper.sv

@@ -1,6 +1,8 @@
 module mapper(
     input i_reset,
     input i_clk,
+    input i_clk50,
+    input i_clk100,
     input i_cs,
     input i_we,
     input [7:0] i_data,
@@ -10,6 +12,7 @@ module mapper(
 );
 
 logic [15:0] mm [16];
+logic [15:0] _mm [16];
 logic [15:0] mm_next [16];
 
 logic [31:0] we;
@@ -20,13 +23,14 @@ logic [15:0] mm_sel;
 
 logic [15:0] selected_mm;
 
+logic [15:0] _cpu_addr;
+
 always_comb begin
     we = ((i_we & i_cs) << i_cpu_addr[4:0]);
 
     mm_sel = (1 << i_cpu_addr[4:1]);
     o_data = mm_sel[8*i_cpu_addr[0] +: 8];
 
-    selected_mm = mm[i_cpu_addr[15:12]];
     o_mapped_addr = {selected_mm[12:0], i_cpu_addr[11:0]};
 
     for (int i = 0; i < 16; i++) begin
@@ -40,6 +44,11 @@ always_comb begin
     end
 end
 
+always_ff @(posedge i_clk100) begin
+    _cpu_addr <= i_cpu_addr;
+    selected_mm <= mm[_cpu_addr[15:12]];
+end
+
 always_ff @(negedge i_clk or posedge i_reset) begin
     if (i_reset) begin
         for (int i = 0; i < 16; i++) begin