Add additional exception information to sbe

Moved PC from exception to scoreboard entry as we have the entry
available in the commit stage where we take the exception. Also add the
additional exception information which we need to set the s/mval field.

include/ariane_pkg.svh

@@ -31,17 +31,18 @@ package ariane_pkg;
     // Only use struct when signals have same direction
     // exception
     typedef struct packed {
-         logic [63:0] epc;
-         logic [63:0] cause;
+         logic [63:0] cause; // cause of exception
+         logic [63:0] tval;  // additional information of causing exception (e.g.: instruction causing it),
+                             // address of ld/st fault
          logic        valid;
     } exception;
 
     // miss-predict
     typedef struct packed {
-         logic [63:0] pc;
-         logic [63:0] target_address;
-         logic        is_taken;
-         logic        valid; // is miss-predict
+        logic [63:0] pc;
+        logic [63:0] target_address;
+        logic        is_taken;
+        logic        valid; // is miss-predict
     } misspredict;
 
     typedef enum logic[3:0] {
@@ -49,10 +50,10 @@ package ariane_pkg;
     } fu_t;
 
     localparam EXC_OFF_RST      = 8'h80;
+
     // ---------------
     // EX Stage
     // ---------------
-
     typedef enum logic [7:0] { // basic ALU op
                                ADD, SUB, ADDW, SUBW,
                                // logic operations
@@ -73,6 +74,7 @@ package ariane_pkg;
     // ID/EX/WB Stage
     // ---------------
     typedef struct packed {
+        logic [63:0]              pc;            // PC of instruction
         logic [TRANS_ID_BITS-1:0] trans_id;      // this can potentially be simplified, we could index the scoreboard entry
                                                  // with the transaction id in any case make the width more generic
         fu_t                      fu;            // functional unit to use

src/decoder.sv

@@ -46,6 +46,7 @@ module decoder (
 
         imm_select = NOIMM;
         illegal_instr_o = 1'b0;
+        instruction_o.pc = pc_i;
         instruction_o.fu = NONE;
         instruction_o.op = ADD;
         instruction_o.rs1 = 5'b0;

src/if_stage.sv

@@ -197,8 +197,8 @@ module if_stage (
                   illegal_c_insn_id_o <= illegal_c_insn;
                   is_compressed_id_o  <= instr_compressed_int;
                   pc_id_o             <= pc_if_o;
-                  ex_o.epc            <= pc_if_o;
                   ex_o.cause          <= 64'b0; // TODO: Output exception
+                  ex_o.tval           <= 64'b0; // TODO: Output exception
                   ex_o.valid          <= 1'b0;  // TODO: Output exception
               end else if (clear_instr_valid_i) begin
                 instr_valid_id_o    <= 1'b0;

src/issue_read_operands.sv

@@ -178,7 +178,7 @@ module issue_read_operands (
 
         // use the PC as operand a
         if (issue_instr_i.use_pc) begin
-            operand_a_n = issue_instr_i.ex.epc;
+            operand_a_n = issue_instr_i.pc;
         end
 
         // or is it an immediate (including PC), this is not the case for a store

tb/models/scoreboard.sv

@@ -8,7 +8,7 @@ class Scoreboard;
     static function scoreboard_entry randomize_scoreboard();
             exception exception = { 63'h0, 63'h0, 1'b0};
             scoreboard_entry entry = {
-                i, ALU, ADD, 5'h5, 5'h5, 5'h5, 64'h0, 1'b0, 1'b0, exception, 1'b0
+                63'b0, i, ALU, ADD, 5'h5, 5'h5, 5'h5, 64'h0, 1'b0, 1'b0, exception, 1'b0
             };
             return entry;
     endfunction : randomize_scoreboard