恢复is_busy操作时机

tb/shinTest/ShinTopSpiTb.v

@@ -562,7 +562,6 @@ end
 always @(negedge sck) begin
   if( isBusy ) begin
     if( transCnt == length & &bitCnt ) begin
-      isBusy       <= #(`SCKFRE/2) 1'b0;
       spi_csn[idx] <= #(`SCKFRE/2) 1'b1;
     end
   end
@@ -610,6 +609,8 @@ always @(posedge sck) begin
           exChangeRegi <= isQspi ? {exChangeRegi[3:0], qspi_mux_miso} : {exChangeRegi[6:0], spi_mux_miso};
         end
       end
+    end else begin
+      isBusy       <= #5 1'b0;
     end
   end
 end