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Started implementing JAL/JALR target calculation in ALU, improved a few defaults

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Sven Stucki 2015-04-07 18:35:20 +02:00
parent d7e8aba2f9
commit 5d96d3e7a1
2 changed files with 8 additions and 10 deletions
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16
controller.sv
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@ -207,7 +207,7 @@ module controller
extend_immediate_o = 1'b0;
alu_op_a_mux_sel_o = `OP_A_REGA_OR_FWD;
alu_op_b_mux_sel_o = `OP_B_REGB_OR_FWD;
alu_pc_mux_sel_o = 1'b0;
alu_pc_mux_sel_o = 1'b1;
vector_mode_o = `VEC_MODE32;
scalar_replication_o = 1'b0;
@ -315,12 +315,11 @@ module controller
`OPCODE_JAL: begin // Jump and Link
if (instr_rdata_i ==? `INSTR_JAL) begin
pc_mux_sel_o = `PC_FROM_IMM;
alu_pc_mux_sel_o = 1'b1;
pc_mux_sel_o = `PC_FROM_ALU;
alu_op_a_mux_sel_o = `OP_A_CURRPC;
alu_op_b_mux_sel_o = `OP_B_IMM;
immediate_mux_sel_o = `IMM_C4;
alu_operator = `ALU_ADD;
immediate_mux_sel_o = `IMM_UJ;
alu_operator = `ALU_JAL;
regfile_alu_we = 1'b1;
end else begin
illegal_insn_o = 1'b1;
@ -329,11 +328,10 @@ module controller
`OPCODE_JALR: begin // Jump and Link Register
if (instr_rdata_i ==? `INSTR_JALR) begin
pc_mux_sel_o = `PC_FROM_REGFILE;
alu_op_a_mux_sel_o = `OP_A_CURRPC;
pc_mux_sel_o = `PC_FROM_ALU;
alu_op_b_mux_sel_o = `OP_B_IMM;
immediate_mux_sel_o = `IMM_C4;
alu_operator = `ALU_ADD;
immediate_mux_sel_o = `IMM_I;
alu_operator = `ALU_JAL;
regfile_alu_we = 1'b1;
rega_used = 1'b1;
end else begin

2
id_stage.sv
View file

@ -346,7 +346,7 @@ module id_stage
always_comb
begin : alu_pc_mux
case (alu_pc_mux_sel)
1'b0: current_pc = current_pc_if_i;
1'b0: current_pc = current_pc_if_i; // TODO: FIXME 1'b0 is never used
1'b1: current_pc = current_pc_id_i;
endcase; // case (alu_pc_mux_sel)
end