diff options
| -rw-r--r-- | src/rtl/montprod.v | 53 |
1 files changed, 35 insertions, 18 deletions
diff --git a/src/rtl/montprod.v b/src/rtl/montprod.v index f505d0c..9748b09 100644 --- a/src/rtl/montprod.v +++ b/src/rtl/montprod.v @@ -127,7 +127,7 @@ module montprod( reg [04 : 0] b_bit_index_reg; reg [04 : 0] b_bit_index_new; - reg b_bit_index_we; + reg [04 : 0] b_bit_index_we; reg [07 : 0] word_index_reg; //register of what word is being read reg [07 : 0] word_index_new; //calculation of what word to be read @@ -157,7 +157,7 @@ module montprod( wire [31 : 0] add_result_sm; wire add_carry_out_sm; - reg [31 : 0] shr_data_in; + reg shr_data_in; wire shr_carry_out; wire [31 : 0] shr_data_out; @@ -331,19 +331,44 @@ module montprod( //---------------------------------------------------------------- always @* begin : s_select_write - sa_adder_data_in = 32'h0; - shr_carry_in_new = 1'b0; + shr_carry_in_new = 1'b0; + s_mux_new = SMUX_0; + s_mem_we_new = 1'b0; + sa_adder_data_in = 32'h0; + + case (montprod_ctrl_reg) + CTRL_INIT_S: + begin + s_mux_new = SMUX_0; // write 0 + s_mem_we_new = 1'b1; + end + + CTRL_L_CALC_SA: + begin + //s = (s + q*M + b*A) >>> 1;, if(b==1) S+= A. Takes (1..length) cycles. + s_mux_new = SMUX_ADD_SA; + s_mem_we_new = b_reg | q_reg; + end + + CTRL_L_CALC_SDIV2: + begin + //s = (s + q*M + b*A) >>> 1; s>>=1. Takes (1..length) cycles. + s_mux_new = SMUX_SHR; + s_mem_we_new = 1'b1; + end + + default: + begin + end + endcase + + s_mem_new = 32'h0; add_carry_in_sa_new = 1'b0; add_carry_in_sm_new = 1'b0; - s_mem_new = 32'h0; - s_mem_we_new = 1'b0; case (s_mux_reg) SMUX_0: - begin - s_mem_new = 32'h0; - s_mem_we_new = 1'b1; - end + s_mem_new = 32'h0; SMUX_ADD_SA: begin @@ -359,7 +384,6 @@ module montprod( add_carry_in_sa_new = add_carry_out_sa; add_carry_in_sm_new = add_carry_out_sm; - s_mem_we_new = b_reg | q_reg; end SMUX_SHR: @@ -367,7 +391,6 @@ module montprod( shr_data_in = s_mem_read_data; s_mem_new = shr_data_out; shr_carry_in_new = shr_carry_out; - s_mem_we_new = 1'b1; end default: @@ -460,8 +483,6 @@ module montprod( CTRL_INIT_S: begin - s_mux_new = SMUX_0; - if (word_index_reg == 8'h0) begin loop_ctr_set = 1'b1; @@ -496,8 +517,6 @@ module montprod( CTRL_L_CALC_SA: begin - s_mux_new = SMUX_ADD_SA; - if (word_index_reg == 8'h0) begin reset_word_index_lsw = 1'b1; @@ -515,8 +534,6 @@ module montprod( CTRL_L_CALC_SDIV2: begin - s_mux_new = SMUX_SHR; - if (word_index_reg == length_m1) begin montprod_ctrl_new = CTRL_L_STALLPIPE_D2; |