path: root/rtl/modexpng_microcode.vh

localparam UOP_OPCODE_W = 4;
localparam UOP_CRT_W    = 1;
localparam UOP_NPQ_W    = 1;
localparam UOP_AUX_W    = 1;
localparam UOP_LADDER_W = 1;
localparam UOP_SEL_W    = 4 * BANK_ADDR_W;

localparam UOP_ADDR_W = 6;  // 64 instructions

localparam [UOP_ADDR_W -1:0] UOP_ADDR_OFFSET_USING_CRT = 6'd0;
localparam [UOP_ADDR_W -1:0] UOP_ADDR_OFFSET_WITHOUT_CRT = 6'd31;


//                 4              1           1           1           2              4*3=12
localparam UOP_W = UOP_OPCODE_W + UOP_CRT_W + UOP_NPQ_W + UOP_AUX_W + UOP_LADDER_W + UOP_SEL_W;
//                 [20:17]        [16]        [15]        [14]        [13:12]        [11:9][8:6][5:3][2:0]

// OPCODE
localparam [UOP_OPCODE_W -1:0] UOP_OPCODE_STOP               = 4'd0;
/* all fields are don't care
 */

localparam [UOP_OPCODE_W -1:0] UOP_OPCODE_INPUT_TO_WIDE      = 4'd1;
localparam [UOP_OPCODE_W -1:0] UOP_OPCODE_INPUT_TO_NARROW    = 4'd2;
/* CRT tells into which of the dual MMM to write
 * NPQ specifies the width of the operand
 * AUX specifies from which INPUT to read
 * LADDER is don't care
 * source WIDE is always don't care
 * destination NARROW is don't care for _WIDE opcode and vice versa
 * 
*/

localparam [UOP_OPCODE_W -1:0] UOP_OPCODE_OUTPUT_FROM_NARROW = 4'd3;

//localparam [UOP_OPCODE_W -1:0] UOP_OPCODE_COPY_CRT_Y2X  = 4'd0;

localparam [UOP_OPCODE_W -1:0] UOP_OPCODE_MODULAR_MULTIPLY   = 4'd8;
/* CRT is don't care
 * NPQ specifies the width of the operand
 * AUX = AUX_2 forces B input to 1 (AUX_1 reads from source NARROW as usual)
 * LADDER specifies Montgomery ladder mode 
 */

// CRT
localparam [UOP_CRT_W -1:0] UOP_CRT_X   = 1'b0;
localparam [UOP_CRT_W -1:0] UOP_CRT_Y   = 1'b1;
localparam [UOP_CRT_W -1:0] UOP_CRT_DNC = 1'bX;

// NPQ
localparam [UOP_NPQ_W -1:0] UOP_NPQ_N   = 1'b0;
localparam [UOP_NPQ_W -1:0] UOP_NPQ_PQ  = 1'b1;
localparam [UOP_NPQ_W -1:0] UOP_NPQ_DNC = 1'bX;

// AUX
localparam [UOP_AUX_W -1:0] UOP_AUX_1   = 1'b0;
localparam [UOP_AUX_W -1:0] UOP_AUX_2   = 1'b1;
localparam [UOP_AUX_W -1:0] UOP_AUX_DNC = 1'bX;

// LADDER
localparam [UOP_LADDER_W -1:0] UOP_LADDER_00  = 2'b00;
localparam [UOP_LADDER_W -1:0] UOP_LADDER_11  = 2'b11;
localparam [UOP_LADDER_W -1:0] UOP_LADDER_D   = 2'b01;
localparam [UOP_LADDER_W -1:0] UOP_LADDER_PQ  = 2'b10;
localparam [UOP_LADDER_W -1:0] UOP_LADDER_DNC = 2'bXX;


// SEL
localparam [UOP_SEL_W -1:0] UOP_SEL_DNC_ALL = {4{BANK_DNC}};