diff options
Diffstat (limited to 'design/stack_machine.v')
| -rw-r--r-- | design/stack_machine.v | 45 |
1 files changed, 38 insertions, 7 deletions
diff --git a/design/stack_machine.v b/design/stack_machine.v index 54eae5e..91e808b 100644 --- a/design/stack_machine.v +++ b/design/stack_machine.v @@ -206,10 +206,18 @@ module stack_machine_new assign instr_tee = !set_im && !use_im && stack_grows && instruction[11:0] == 12'd0; + wire instr_get_frame; + assign instr_get_frame = !set_im && !use_im && stack_grows && + instruction[11:0] == 12'd1; + wire instr_const; assign instr_const = use_im && stack_grows && instruction[11:7] == 5'd0; + wire instr_call; + assign instr_call = use_im && stack_grows && + instruction[11:7] == 5'd1; + /* Instructions, that shrink stack */ wire instr_add; assign instr_add = !set_im && !use_im && stack_shrinks_by_1 && @@ -227,6 +235,14 @@ module stack_machine_new assign instr_mul = !set_im && !use_im && stack_shrinks_by_1 && instruction[11:0] == 12'd3; + wire instr_drop; + assign instr_drop = !set_im && !use_im && stack_shrinks_by_1 && + instruction[11:0] == 12'd4; + + wire instr_ret; + assign instr_ret = !set_im && !use_im && stack_shrinks_by_1 && + instruction[11:0] == 12'b000010000000; + wire instr_cond_jump; assign instr_cond_jump = use_im && stack_shrinks_by_1 && instruction[11:7] == 5'd1; @@ -366,8 +382,6 @@ module stack_machine_new I_CYC_O <= 1; D_CYC_O <= 0; - D_STB_O <= 0; - D_WE_O <= 0; end if (first_execution_tick) begin @@ -434,8 +448,9 @@ module stack_machine_new <= {stack_transfer_unrequested[0], 1'b0}; end - if (load_store_unrequested || - stack_transfer_unrequested[0]) begin + if (stack_transfer_unrequested[0] || + (load_store_unrequested && + stack_transfer_unrequested[1])) begin if (stack_shrinks) begin `SET_SP(sp + 4); D_ADR_O <= sp; @@ -443,7 +458,7 @@ module stack_machine_new D_SEL_O <= 4'b1111; D_STB_O <= 1; D_WE_O <= 0; - end else if (stack_grows) begin + end else /* if (stack_grows) */ begin `SET_SP(sp - 4); D_ADR_O <= sp - 4; D_DAT_O <= stack_put_value; @@ -451,13 +466,13 @@ module stack_machine_new D_STB_O <= 1; D_WE_O <= 1; end - end else begin // if (load_store_unrequested ||... + end else begin // if (stack_transfer_unrequested[0] ||... D_ADR_O <= 21'bx; D_DAT_O <= 32'bx; D_SEL_O <= 4'bx; D_STB_O <= 0; D_WE_O <= 0; - end // else: !if(load_store_unrequested ||... + end // else: !if(stack_transfer_unrequested[0] ||... end // if (data_request_happens) if (data_command_completes) begin @@ -521,9 +536,17 @@ module stack_machine_new if (instr_tee) r1 <= r1; + if (instr_get_frame && first_execution_tick) + r1 <= sp; + if (instr_const && first_execution_tick) r1 <= im_effective; + if (instr_call && first_execution_tick) begin + r1 <= pc; + `SET_PC(im_effective); + end + /* Instructions, that shrink stack */ if (instr_add && arithmetic_uncompleted) r1 <= r0 + r1; @@ -537,12 +560,20 @@ module stack_machine_new if (instr_mul && arithmetic_uncompleted) r1 <= r0 * r1; + if (instr_drop && arithmetic_uncompleted) + r1 <= r0; + if (instr_cond_jump && arithmetic_uncompleted) begin r1 <= r0; if (r1) `SET_PC(im_effective); end + + if (instr_ret && arithmetic_uncompleted) begin + r1 <= r0; + `SET_PC(r1); + end end // case: STEP_EXECUTING endcase // case (step) end // else: !if(RST_I) |