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authorJoachim StroĢˆmbergson <joachim@secworks.se>2015-06-18 12:44:46 +0200
committerJoachim StroĢˆmbergson <joachim@secworks.se>2015-06-18 12:44:46 +0200
commit1e676b4c463e6a5e75a4d81578b139a51059a601 (patch)
treefa56dade05b7ed5607c681989db15f47215abb85 /src/rtl
parent90337c66cc1a644b27a4ed8e188b1aa4e07fea67 (diff)
Adding iteration flag to be used to remove zero fill of s_mem.
Diffstat (limited to 'src/rtl')
-rw-r--r--src/rtl/montprod.v55
1 files changed, 30 insertions, 25 deletions
diff --git a/src/rtl/montprod.v b/src/rtl/montprod.v
index 465bd70..cd7d5a9 100644
--- a/src/rtl/montprod.v
+++ b/src/rtl/montprod.v
@@ -142,10 +142,9 @@ module montprod(
reg shr_carry_in_reg;
reg shr_carry_in_new;
- reg reset_word_index_lsw;
- reg reset_word_index_msw;
-
- reg [31 : 0] sa_adder_data_in;
+ reg first_iteration_reg;
+ reg first_iteration_new;
+ reg first_iteration_we;
//----------------------------------------------------------------
@@ -161,6 +160,11 @@ module montprod(
wire shr_carry_out;
wire [31 : 0] shr_data_out;
+ reg reset_word_index_lsw;
+ reg reset_word_index_msw;
+
+ reg [31 : 0] sa_adder_data_in;
+
//----------------------------------------------------------------
@@ -226,7 +230,7 @@ module montprod(
begin : reg_update
if (!reset_n)
begin
- ready_reg <= 1'b0;
+ ready_reg <= 1'b1;
loop_ctr_reg <= 13'h0;
word_index_reg <= 8'h0;
word_index_prev_reg <= 8'h0;
@@ -239,6 +243,7 @@ module montprod(
s_mem_we_reg <= 1'b0;
s_mem_wr_addr_reg <= 8'h0;
b_bit_index_reg <= 5'h0;
+ first_iteration_reg <= 1'b0;
montprod_ctrl_reg <= CTRL_IDLE;
end
else
@@ -254,6 +259,9 @@ module montprod(
add_carry_in_sa_reg <= add_carry_in_sa_new;
add_carry_in_sm_reg <= add_carry_in_sm_new;
+ if (first_iteration_we)
+ first_iteration_reg <= first_iteration_new;
+
if (b_bit_index_we)
b_bit_index_reg <= b_bit_index_new;
@@ -445,21 +453,19 @@ module montprod(
//----------------------------------------------------------------
always @*
begin : montprod_ctrl
- ready_new = 1'b0;
- ready_we = 1'b0;
- montprod_ctrl_new = CTRL_IDLE;
- montprod_ctrl_we = 1'b0;
-
- loop_ctr_set = 1'b0;
- loop_ctr_dec = 1'b0;
- b_bit_index_we = 1'b0;
- bq_we = 1'b0;
-
- s_mux_new = SMUX_0;
-
+ ready_new = 1'b0;
+ ready_we = 1'b0;
+ loop_ctr_set = 1'b0;
+ loop_ctr_dec = 1'b0;
+ b_bit_index_we = 1'b0;
+ bq_we = 1'b0;
+ s_mux_new = SMUX_0;
reset_word_index_lsw = 1'b0;
reset_word_index_msw = 1'b0;
-
+ first_iteration_new = 1'b0;
+ first_iteration_we = 1'b0;
+ montprod_ctrl_new = CTRL_IDLE;
+ montprod_ctrl_we = 1'b0;
case (montprod_ctrl_reg)
CTRL_IDLE:
@@ -468,14 +474,11 @@ module montprod(
begin
ready_new = 1'b0;
ready_we = 1'b1;
- montprod_ctrl_new = CTRL_INIT_S;
- montprod_ctrl_we = 1'b1;
reset_word_index_lsw = 1'b1;
- end
- else
- begin
- ready_new = 1'b1;
- ready_we = 1'b1;
+ first_iteration_new = 1'b1;
+ first_iteration_we = 1'b1;
+ montprod_ctrl_new = CTRL_INIT_S;
+ montprod_ctrl_we = 1'b1;
end
end
@@ -529,6 +532,8 @@ module montprod(
CTRL_L_STALLPIPE_SA:
begin
+ first_iteration_new = 1'b0;
+ first_iteration_we = 1'b1;
montprod_ctrl_new = CTRL_L_CALC_SDIV2;
montprod_ctrl_we = 1'b1;
reset_word_index_msw = 1'b1;