diff --git a/opene906/demo/sim/Makefile b/opene906/demo/sim/Makefile
index e85b3e2..ee520de 100644
--- a/opene906/demo/sim/Makefile
+++ b/opene906/demo/sim/Makefile
@@ -72,7 +72,8 @@ openocd:
 # openocd -f riscv.cfg -d3
 
 gdb:
-	$(GDB_PREFIX) -x gdbinit ./build/$(TEST).bin
+# $(GDB_PREFIX) -x gdbinit ./build/$(TEST).bin
+	$(GDB_PREFIX) -x gdbinit ./work/debug.elf
 
 help:
 	@echo Possible targets: verilator help clean all verilator-build program.hex
diff --git a/opene906/demo/sim/dpi/jtagdpi/jtagdpi.sv b/opene906/demo/sim/dpi/jtagdpi/jtagdpi.sv
index 451efed..621684b 100644
--- a/opene906/demo/sim/dpi/jtagdpi/jtagdpi.sv
+++ b/opene906/demo/sim/dpi/jtagdpi/jtagdpi.sv
@@ -32,7 +32,7 @@ module jtagdpi #(
     input bit tdo
   );
 
-  reg [2:0] plit;
+  reg [1:0] plit;
 
   import "DPI-C" function void jtagdpi_close(input chandle ctx);
 
@@ -49,7 +49,7 @@ module jtagdpi #(
 
   always_ff @(posedge clk_i) plit <= plit + 1'b1;
 
-  always_ff @(posedge plit[2], negedge rst_ni) begin
+  always_ff @(posedge plit[1], negedge rst_ni) begin
     jtagdpi_tick(ctx, jtag_tck, jtag_tms, jtag_tdi, jtag_trst_n, jtag_srst_n,
                  jtag_tdo);
   end
diff --git a/opene906/demo/sim/work/Makefile b/opene906/demo/sim/work/Makefile
index 6d54d32..497a650 100644
--- a/opene906/demo/sim/work/Makefile
+++ b/opene906/demo/sim/work/Makefile
@@ -42,9 +42,9 @@ FLAG_ABI   = -mabi=ilp32f
 CFLAGS = ${FLAG_MARCH} ${FLAG_ABI} 
 
 ifeq (${CASENAME}, coremark)
-  CFLAGS +=-c -v -O3 -funroll-all-loops -fgcse-sm -finline-limit=500 -fno-schedule-insns --param max-rtl-if-conversion-unpredictable-cost=100 -msignedness-cmpiv -fno-code-hoisting -mno-thread-jumps1 -mno-iv-adjust-addr-cost -mno-expand-split-imm -fno-tree-loop-distribution
+  CFLAGS +=-c -v -O3 -g -funroll-all-loops -fgcse-sm -finline-limit=500 -fno-schedule-insns --param max-rtl-if-conversion-unpredictable-cost=100 -msignedness-cmpiv -fno-code-hoisting -mno-thread-jumps1 -mno-iv-adjust-addr-cost -mno-expand-split-imm -fno-tree-loop-distribution
 else
-  CFLAGS += -c -v -O2
+  CFLAGS += -c -v -O2 -g
 endif
 
 LINKFLAGS = -Tlinker.lcf -nostartfiles ${FLAG_MARCH} ${FLAG_ABI}
@@ -105,5 +105,5 @@ all :  clean ${FILE}.pat ${FILE}.hex ${FILE}.elf ${FILE}.obj ${FILE}.dis
 # clean some medium code and .pat
 .PHONY :clean 
 clean:
-	rm -rf *.o *.pat  *.obj *.hex *.dis
+	rm -rf *.o *.pat  *.obj *.hex *.dis *.elf