diff --git a/rtl/serv_decode.v b/rtl/serv_decode.v
index 7457b97..c6fcba8 100644
--- a/rtl/serv_decode.v
+++ b/rtl/serv_decode.v
@@ -3,7 +3,6 @@ module serv_decode
   (
    input wire 	     clk,
    //Input
-   input wire 	     i_cnt_en,
    input wire [31:2] i_wb_rdt,
    input wire 	     i_wb_en,
    //To state
@@ -51,7 +50,7 @@ module serv_decode
    output wire 	     o_csr_mcause_en,
    output wire [1:0] o_csr_source,
    output wire 	     o_csr_d_sel,
-   output wire 	     o_csr_imm,
+   output wire 	     o_csr_imm_en,
    //To top
    output wire [3:0] o_immdec_ctrl,
    output wire 	     o_op_b_source,
@@ -146,7 +145,7 @@ module serv_decode
 
    assign o_csr_source = funct3[1:0];
    assign o_csr_d_sel = funct3[2];
-   assign o_csr_imm = o_rf_rs1_addr[0];
+   assign o_csr_imm_en = csr_op & o_csr_d_sel;
 
    assign o_csr_addr = (op26 & !op20) ? CSR_MSCRATCH :
 		       (op26 & !op21) ? CSR_MEPC :
@@ -191,11 +190,6 @@ module serv_decode
 	 op21 <= i_wb_rdt[21];
 	 op22 <= i_wb_rdt[22];
 	 op26 <= i_wb_rdt[26];
-
-      end
-      if (i_cnt_en) begin
-	 if (csr_op & o_csr_d_sel)
-	   o_rf_rs1_addr <= {1'b0,o_rf_rs1_addr[4:1]};
       end
    end
 
diff --git a/rtl/serv_immdec.v b/rtl/serv_immdec.v
index 1e6d61a..974967d 100644
--- a/rtl/serv_immdec.v
+++ b/rtl/serv_immdec.v
@@ -4,6 +4,8 @@ module serv_immdec
    input wire 	     i_clk,
    //Input   
    input wire 	     i_cnt_en,
+   input wire 	     i_csr_imm_en,
+   output wire 	     o_csr_imm,
    input wire [31:2] i_wb_rdt,
    input wire 	     i_wb_en,
    input wire 	     i_cnt_done,
@@ -20,10 +22,11 @@ module serv_immdec
 
 
    assign o_imm = i_cnt_done ? signbit : i_ctrl[0] ? imm11_7[0] : imm24_20[0];
+   assign o_csr_imm = imm19_12_20[4];
 
    always @(posedge i_clk) begin
       if (i_wb_en) begin
-	 signbit     <= i_wb_rdt[31];
+	 signbit     <= i_wb_rdt[31] & !i_csr_imm_en;
 	 imm19_12_20 <= {i_wb_rdt[19:12],i_wb_rdt[20]};
 	 imm7        <= i_wb_rdt[7];
 	 imm30_25    <= i_wb_rdt[30:25];
diff --git a/rtl/serv_top.v b/rtl/serv_top.v
index 501c0b9..3fdebfa 100644
--- a/rtl/serv_top.v
+++ b/rtl/serv_top.v
@@ -143,7 +143,7 @@ module serv_top
    wire 	 csr_en;
    wire [1:0] 	 csr_addr;
    wire 	 csr_pc;
-
+   wire 	csr_imm_en;
 
    wire 	 new_irq;
    wire 	 trap_taken;
@@ -202,7 +202,6 @@ module serv_top
      (
       .clk (clk),
       //Input
-      .i_cnt_en           (cnt_en),
       .i_wb_rdt           (i_ibus_rdt[31:2]),
       .i_wb_en            (o_ibus_cyc & i_ibus_ack),
       //To state
@@ -251,7 +250,7 @@ module serv_top
       .o_csr_mcause_en    (csr_mcause_en),
       .o_csr_source       (csr_source),
       .o_csr_d_sel        (csr_d_sel),
-      .o_csr_imm          (csr_imm),
+      .o_csr_imm_en       (csr_imm_en),
       //To top
       .o_immdec_ctrl      (immdec_ctrl),
       .o_rd_csr_en        (rd_csr_en),
@@ -261,6 +260,8 @@ module serv_top
      (
       .i_clk      (clk),
       .i_cnt_en   (cnt_en),
+      .i_csr_imm_en (csr_imm_en),
+      .o_csr_imm  (csr_imm),
       .i_wb_rdt   (i_ibus_rdt[31:2]),
       .i_wb_en    (o_ibus_cyc & i_ibus_ack),
       .i_ctrl     (immdec_ctrl),