+
+ /* Condition checking logic */
+ reg condition_met_1a;
+ always @(*)
+ casez(insn_1a[31:28])
+ `COND_EQ: condition_met_1a = cpsr_1a[`CPSR_Z];
+ `COND_NE: condition_met_1a = !cpsr_1a[`CPSR_Z];
+ `COND_CS: condition_met_1a = cpsr_1a[`CPSR_C];
+ `COND_CC: condition_met_1a = !cpsr_1a[`CPSR_C];
+ `COND_MI: condition_met_1a = cpsr_1a[`CPSR_N];
+ `COND_PL: condition_met_1a = !cpsr_1a[`CPSR_N];
+ `COND_VS: condition_met_1a = cpsr_1a[`CPSR_V];
+ `COND_VC: condition_met_1a = !cpsr_1a[`CPSR_V];
+ `COND_HI: condition_met_1a = cpsr_1a[`CPSR_C] && !cpsr_1a[`CPSR_Z];
+ `COND_LS: condition_met_1a = !cpsr_1a[`CPSR_C] || cpsr_1a[`CPSR_Z];
+ `COND_GE: condition_met_1a = cpsr_1a[`CPSR_N] == cpsr_1a[`CPSR_V];
+ `COND_LT: condition_met_1a = cpsr_1a[`CPSR_N] != cpsr_1a[`CPSR_V];
+ `COND_GT: condition_met_1a = !cpsr_1a[`CPSR_Z] && (cpsr_1a[`CPSR_N] == cpsr_1a[`CPSR_V]);
+ `COND_LE: condition_met_1a = cpsr_1a[`CPSR_Z] || (cpsr_1a[`CPSR_N] != cpsr_1a[`CPSR_V]);
+ `COND_AL: condition_met_1a = 1;
+ `COND_NV: condition_met_1a = 0;
+ default: condition_met_1a = 1'bx;
+ endcase
+
+ /* Issue logic */
+ /* Once it's hit writeback, it's hit the regfile via forwarding so you're done. */
+ reg cpsr_inflight_2a = 0, cpsr_inflight_3a = 0;
+ reg [15:0] regs_inflight_2a = 0, regs_inflight_3a = 0;
+
+ wire waiting_cpsr_1a = use_cpsr & (cpsr_inflight_2a | cpsr_inflight_3a);
+ wire waiting_regs_1a = |(use_regs & (regs_inflight_2a | regs_inflight_3a));
+ wire waiting_1a = waiting_cpsr_1a | waiting_regs_1a;
+ assign stall_0a = (waiting_1a && !bubble_1a && !flush) || stall_1a;
+
+ reg delayedflush = 0;
+ always @(posedge clk/* or negedge Nrst*/)
+ if (!Nrst)
+ delayedflush <= 0;
+ else if (flush && stall_0a /* halp! I can't do it now, maybe later? */)
+ delayedflush <= 1;
+ else if (!stall_0a /* anything has been handled this time around */)
+ delayedflush <= 0;
+
+ /* Actually do the issue. */
+ always @(posedge clk or negedge Nrst)
+ begin
+ if (waiting_1a)
+ $display("ISSUE: Stalling instruction %08x because %d/%d", insn_1a, waiting_cpsr_1a, waiting_regs_1a);
+
+ if (!Nrst) begin
+ bubble_2a <= 1;
+ /*AUTORESET*/
+ // Beginning of autoreset for uninitialized flops
+ cpsr_inflight_2a <= 1'h0;
+ cpsr_inflight_3a <= 1'h0;
+ insn_2a <= 32'h0;
+ pc_2a <= 32'h0;
+ regs_inflight_2a <= 16'h0;
+ regs_inflight_3a <= 16'h0;
+ // End of automatics
+ end else if (!stall_1a)
+ begin
+ cpsr_inflight_3a <= cpsr_inflight_2a; /* I'm not sure how well selects work with arrays, and that seems like a dumb thing to get anusulated by. */
+ cpsr_inflight_2a <= (waiting_1a || bubble_1a || !condition_met_1a) ? 0 : def_cpsr;
+ regs_inflight_3a <= regs_inflight_2a;
+ regs_inflight_2a <= (waiting_1a || bubble_1a || !condition_met_1a) ? 0 : def_regs;
+
+ bubble_2a <= bubble_1a | waiting_1a | !condition_met_1a | flush | delayedflush;
+ pc_2a <= pc_1a;
+ insn_2a <= insn_1a;
+ end
+ end