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authorJoachim StroĢˆmbergson <joachim@secworks.se>2015-05-20 14:22:42 +0200
committerJoachim StroĢˆmbergson <joachim@secworks.se>2015-05-20 14:22:42 +0200
commitd42084b5a287cd405d15e1b221aa75025802f52f (patch)
tree4056e945478c47839930ae5bca93a434d08f7510 /src/rtl
parentedd192a721f3a5e00fd264c12546301ec1f25571 (diff)
Changed to using modexp length register and removed the common length register.
Diffstat (limited to 'src/rtl')
-rw-r--r--src/rtl/modexp.v31
1 files changed, 7 insertions, 24 deletions
diff --git a/src/rtl/modexp.v b/src/rtl/modexp.v
index 30b703e..58924c5 100644
--- a/src/rtl/modexp.v
+++ b/src/rtl/modexp.v
@@ -143,11 +143,8 @@ module modexp(
reg [07 : 0] modulus_length_new;
reg modulus_length_we;
- reg [07 : 0] length_reg;
- reg [07 : 0] length_new;
reg [07 : 0] length_m1_reg;
reg [07 : 0] length_m1_new;
- reg length_we;
reg start_reg;
reg start_new;
@@ -421,7 +418,6 @@ module modexp(
modexp_ctrl_reg <= CTRL_IDLE;
one_reg <= 32'h0;
b_one_reg <= 32'h0;
- length_reg <= DEFAULT_MODLENGTH;
length_m1_reg <= 8'h0;
loop_counter_reg <= 13'b0;
ei_reg <= 1'b0;
@@ -438,7 +434,10 @@ module modexp(
exponent_length_reg <= exponent_length_new;
if (modulus_length_we)
- modulus_length_reg <= modulus_length_new;
+ begin
+ modulus_length_reg <= modulus_length_new;
+ length_m1_reg <= length_m1_new;
+ end
if (start_we)
start_reg <= start_new;
@@ -455,12 +454,6 @@ module modexp(
if (modexp_ctrl_we)
modexp_ctrl_reg <= modexp_ctrl_new;
- if (length_we)
- begin
- length_reg <= length_new;
- length_m1_reg <= length_m1_new;
- end
-
if (loop_counter_we)
loop_counter_reg <= loop_counter_new;
@@ -484,7 +477,6 @@ module modexp(
exponent_length_we = 1'b0;
start_new = 1'b0;
start_we = 1'b0;
- length_we = 1'b0;
invalidate_residue = 1'b0;
modulus_mem_api_rst = 1'b0;
@@ -509,7 +501,6 @@ module modexp(
exponation_mode_new = EXPONATION_MODE_SECRET_SECURE;
modulus_length_new = write_data[7 : 0];
exponent_length_new = write_data[7 : 0];
- length_new = write_data[7 : 0];
length_m1_new = write_data[7 : 0] - 8'h1;
tmp_read_data = 32'h00000000;
@@ -546,11 +537,6 @@ module modexp(
exponent_length_we = 1'b1;
end
- ADDR_LENGTH:
- begin
- length_we = 1'b1;
- end
-
ADDR_MODULUS_PTR_RST:
begin
modulus_mem_api_rst = 1'b1;
@@ -619,9 +605,6 @@ module modexp(
ADDR_EXPONENT_LENGTH:
tmp_read_data = {24'h000000, exponent_length_reg};
- ADDR_LENGTH:
- tmp_read_data = {24'h000000, length_reg};
-
ADDR_MODULUS_DATA:
begin
modulus_mem_api_cs = 1'b1;
@@ -697,8 +680,8 @@ module modexp(
always @*
begin : residue_process
//N*2, N=length*32, *32 = shl5, *64 = shl6
- residue_nn = { 1'b0, length_reg, 6'h0 };
- residue_length = length_reg;
+ residue_nn = { 1'b0, modulus_length_reg, 6'h0 };
+ residue_length = modulus_length_reg;
residue_opm_data = modulus_mem_int_rd_data;
end
@@ -726,7 +709,7 @@ module modexp(
always @*
begin : montprod_op_select
- montprod_length = length_reg;
+ montprod_length = modulus_length_reg;
result_mem_int_rd_addr = montprod_opa_addr;
message_mem_int_rd_addr = montprod_opa_addr;