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picorv32
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Moved cpuregs read/write to extra always blocks

This commit is contained in:
Clifford Wolf 2016-08-31 11:50:07 +02:00
parent 82d837bf96
commit c9519df01b
1 changed files with 79 additions and 45 deletions
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124
picorv32.v
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@ -1063,9 +1063,6 @@ module picorv32 #(
if (cpu_state == cpu_state_ldmem) dbg_ascii_state = "ldmem";
end
reg cpuregs_write;
reg [31:0] cpuregs_wrdata;
reg set_mem_do_rinst;
reg set_mem_do_rdata;
reg set_mem_do_wdata;
@ -1166,14 +1163,62 @@ module picorv32 #(
clear_prefetched_high_word = COMPRESSED_ISA;
end
reg cpuregs_write;
reg [31:0] cpuregs_wrdata;
reg [31:0] cpuregs_rs1;
reg [31:0] cpuregs_rs2;
reg [regindex_bits-1:0] decoded_rs;
always @* begin
cpuregs_write = 0;
cpuregs_wrdata = 'bx;
if (cpu_state == cpu_state_fetch) begin
(* parallel_case *)
case (1'b1)
latched_branch: begin
cpuregs_wrdata = reg_pc + (latched_compr ? 2 : 4);
cpuregs_write = 1;
end
latched_store && !latched_branch: begin
cpuregs_wrdata = latched_stalu ? alu_out_q : reg_out;
cpuregs_write = 1;
end
ENABLE_IRQ && irq_state[0]: begin
cpuregs_wrdata = reg_next_pc | latched_compr;
cpuregs_write = 1;
end
ENABLE_IRQ && irq_state[1]: begin
cpuregs_wrdata = irq_pending & ~irq_mask;
cpuregs_write = 1;
end
endcase
end
end
always @(posedge clk) begin
if (cpuregs_write)
cpuregs[latched_rd] <= cpuregs_wrdata;
end
always @* begin
decoded_rs = 'bx;
if (ENABLE_REGS_DUALPORT) begin
cpuregs_rs1 = decoded_rs1 ? cpuregs[decoded_rs1] : 0;
cpuregs_rs2 = decoded_rs2 ? cpuregs[decoded_rs2] : 0;
end else begin
decoded_rs = (cpu_state == cpu_state_ld_rs2) ? decoded_rs2 : decoded_rs1;
cpuregs_rs1 = decoded_rs ? cpuregs[decoded_rs] : 0;
cpuregs_rs2 = cpuregs_rs1;
end
end
assign launch_next_insn = cpu_state == cpu_state_fetch && decoder_trigger && (!ENABLE_IRQ || irq_delay || irq_active || !(irq_pending & ~irq_mask));
always @(posedge clk) begin
trap <= 0;
reg_sh <= 'bx;
reg_out <= 'bx;
cpuregs_write = 0;
cpuregs_wrdata = 'bx;
set_mem_do_rinst = 0;
set_mem_do_rdata = 0;
set_mem_do_wdata = 0;
@ -1269,32 +1314,21 @@ module picorv32 #(
latched_branch: begin
current_pc = latched_store ? (latched_stalu ? alu_out_q : reg_out) : reg_next_pc;
`debug($display("ST_RD: %2d 0x%08x, BRANCH 0x%08x", latched_rd, reg_pc + (latched_compr ? 2 : 4), current_pc);)
cpuregs_wrdata = reg_pc + (latched_compr ? 2 : 4);
cpuregs_write = 1;
end
latched_store && !latched_branch: begin
`debug($display("ST_RD: %2d 0x%08x", latched_rd, latched_stalu ? alu_out_q : reg_out);)
cpuregs_wrdata = latched_stalu ? alu_out_q : reg_out;
cpuregs_write = 1;
end
ENABLE_IRQ && irq_state[0]: begin
cpuregs_wrdata = current_pc | latched_compr;
cpuregs_write = 1;
current_pc = PROGADDR_IRQ;
irq_active <= 1;
mem_do_rinst <= 1;
end
ENABLE_IRQ && irq_state[1]: begin
eoi <= irq_pending & ~irq_mask;
cpuregs_wrdata = irq_pending & ~irq_mask;
cpuregs_write = 1;
next_irq_pending = next_irq_pending & irq_mask;
end
endcase
if (cpuregs_write)
cpuregs[latched_rd] <= cpuregs_wrdata;
if (ENABLE_TRACE && latched_trace) begin
latched_trace <= 0;
trace_valid <= 1;
@ -1365,13 +1399,13 @@ module picorv32 #(
case (1'b1)
(CATCH_ILLINSN || WITH_PCPI) && instr_trap: begin
if (WITH_PCPI) begin
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
reg_op1 <= decoded_rs1 ? cpuregs[decoded_rs1] : 0;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
reg_op1 <= cpuregs_rs1;
if (ENABLE_REGS_DUALPORT) begin
pcpi_valid <= 1;
`debug($display("LD_RS2: %2d 0x%08x", decoded_rs2, decoded_rs2 ? cpuregs[decoded_rs2] : 0);)
reg_sh <= decoded_rs2 ? cpuregs[decoded_rs2] : 0;
reg_op2 <= decoded_rs2 ? cpuregs[decoded_rs2] : 0;
`debug($display("LD_RS2: %2d 0x%08x", decoded_rs2, cpuregs_rs2);)
reg_sh <= cpuregs_rs2;
reg_op2 <= cpuregs_rs2;
if (pcpi_int_ready) begin
mem_do_rinst <= 1;
pcpi_valid <= 0;
@ -1425,14 +1459,14 @@ module picorv32 #(
cpu_state <= cpu_state_exec;
end
ENABLE_IRQ && ENABLE_IRQ_QREGS && instr_getq: begin
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
reg_out <= decoded_rs1 ? cpuregs[decoded_rs1] : 0;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
reg_out <= cpuregs_rs1;
latched_store <= 1;
cpu_state <= cpu_state_fetch;
end
ENABLE_IRQ && ENABLE_IRQ_QREGS && instr_setq: begin
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
reg_out <= decoded_rs1 ? cpuregs[decoded_rs1] : 0;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
reg_out <= cpuregs_rs1;
latched_rd <= latched_rd | irqregs_offset;
latched_store <= 1;
cpu_state <= cpu_state_fetch;
@ -1442,39 +1476,39 @@ module picorv32 #(
irq_active <= 0;
latched_branch <= 1;
latched_store <= 1;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
reg_out <= decoded_rs1 ? cpuregs[decoded_rs1] : 0;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
reg_out <= cpuregs_rs1;
cpu_state <= cpu_state_fetch;
end
ENABLE_IRQ && instr_maskirq: begin
latched_store <= 1;
reg_out <= irq_mask;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
irq_mask <= (decoded_rs1 ? cpuregs[decoded_rs1] : 0) | MASKED_IRQ;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
irq_mask <= cpuregs_rs1 | MASKED_IRQ;
cpu_state <= cpu_state_fetch;
end
ENABLE_IRQ && ENABLE_IRQ_TIMER && instr_timer: begin
latched_store <= 1;
reg_out <= timer;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
timer <= decoded_rs1 ? cpuregs[decoded_rs1] : 0;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
timer <= cpuregs_rs1;
cpu_state <= cpu_state_fetch;
end
is_lb_lh_lw_lbu_lhu: begin
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
reg_op1 <= decoded_rs1 ? cpuregs[decoded_rs1] : 0;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
reg_op1 <= cpuregs_rs1;
cpu_state <= cpu_state_ldmem;
mem_do_rinst <= 1;
end
is_slli_srli_srai && !BARREL_SHIFTER: begin
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
reg_op1 <= decoded_rs1 ? cpuregs[decoded_rs1] : 0;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
reg_op1 <= cpuregs_rs1;
reg_sh <= decoded_rs2;
cpu_state <= cpu_state_shift;
end
is_jalr_addi_slti_sltiu_xori_ori_andi, is_slli_srli_srai && BARREL_SHIFTER: begin
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
reg_op1 <= decoded_rs1 ? cpuregs[decoded_rs1] : 0;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
reg_op1 <= cpuregs_rs1;
reg_op2 <= is_slli_srli_srai && BARREL_SHIFTER ? decoded_rs2 : decoded_imm;
if (TWO_CYCLE_ALU)
alu_wait <= 1;
@ -1483,12 +1517,12 @@ module picorv32 #(
cpu_state <= cpu_state_exec;
end
default: begin
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, decoded_rs1 ? cpuregs[decoded_rs1] : 0);)
reg_op1 <= decoded_rs1 ? cpuregs[decoded_rs1] : 0;
`debug($display("LD_RS1: %2d 0x%08x", decoded_rs1, cpuregs_rs1);)
reg_op1 <= cpuregs_rs1;
if (ENABLE_REGS_DUALPORT) begin
`debug($display("LD_RS2: %2d 0x%08x", decoded_rs2, decoded_rs2 ? cpuregs[decoded_rs2] : 0);)
reg_sh <= decoded_rs2 ? cpuregs[decoded_rs2] : 0;
reg_op2 <= decoded_rs2 ? cpuregs[decoded_rs2] : 0;
`debug($display("LD_RS2: %2d 0x%08x", decoded_rs2, cpuregs_rs2);)
reg_sh <= cpuregs_rs2;
reg_op2 <= cpuregs_rs2;
(* parallel_case *)
case (1'b1)
is_sb_sh_sw: begin
@ -1514,9 +1548,9 @@ module picorv32 #(
end
cpu_state_ld_rs2: begin
`debug($display("LD_RS2: %2d 0x%08x", decoded_rs2, decoded_rs2 ? cpuregs[decoded_rs2] : 0);)
reg_sh <= decoded_rs2 ? cpuregs[decoded_rs2] : 0;
reg_op2 <= decoded_rs2 ? cpuregs[decoded_rs2] : 0;
`debug($display("LD_RS2: %2d 0x%08x", decoded_rs2, cpuregs_rs2);)
reg_sh <= cpuregs_rs2;
reg_op2 <= cpuregs_rs2;
(* parallel_case *)
case (1'b1)