design/sys/iop/dmu/rtl/dmu_mmu_qcb_qmc.v

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//
// OpenSPARC T2 Processor File: dmu_mmu_qcb_qmc.v
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module dmu_mmu_qcb_qmc
  (
   clk,                         // clock
   rst_l,                       // reset
   csr2qcb_ds_a,                // csr debug select a
   csr2qcb_ds_b,                // csr debug select b
   irb2qcb_enq,                 // irb srm enqueue
   orb2qcb_full,                // orb isr queue full
   tcb2qcb_hld,                 // tcb hold
   tcb2qcb_vld,                 // tcb valid bits
   qpc2qmc_vld,                 // qpc valid bits
   qrc2qmc_vld,                 // qrc valid bits
   qvc2qmc_vld,                 // qvc valid bits
   qcb2csr_dbg_a,               // csr debug bus a
   qcb2csr_dbg_b,               // csr debug bus b
   qcb2csr_paq,                 // csr physical address queue not empty
   qcb2csr_vaq,                 // csr virtual address queue not empty
   qcb2irb_full,                // irb queue full
   qcb2orb_enq,                 // orb srm enqueue
   qcb2tcb_hld,                 // tcb hold
   qcb2tcb_vld,                 // tcb valid
   qmc2qpc_enq,                 // qpc enqueue
   qmc2qpc_deq,                 // qpc dequeue
   qmc2qrc_enq,                 // qrc enqueue
   qmc2qrc_deq,                 // qrc dequeue
   qmc2qvc_enq,                 // qvc enqueue
   qmc2qvc_deq                  // qvc dequeue
   );

// ----------------------------------------------------------------------------
// Ports
// ----------------------------------------------------------------------------
  input                                 clk;
  input                                 rst_l;

  input [`FIRE_DLC_MMU_CSR_DS_BITS]     csr2qcb_ds_a;
  input [`FIRE_DLC_MMU_CSR_DS_BITS]     csr2qcb_ds_b;
  input                                 irb2qcb_enq;
  input                                 orb2qcb_full;
  input                                 tcb2qcb_hld;
  input [`FIRE_DLC_MMU_PLS_DPTH:1]      tcb2qcb_vld;
  input [`FIRE_DLC_MMU_PAQ_DPTH-1:0]    qpc2qmc_vld;
  input [`FIRE_DLC_MMU_RDQ_DPTH-1:0]    qrc2qmc_vld;
  input [`FIRE_DLC_MMU_VAQ_DPTH-1:0]    qvc2qmc_vld;

  output [`FIRE_DBG_DATA_BITS]          qcb2csr_dbg_a;
  output [`FIRE_DBG_DATA_BITS]          qcb2csr_dbg_b;
  output                                qcb2csr_paq;
  output                                qcb2csr_vaq;
  output                                qcb2irb_full;
  output                                qcb2orb_enq;
  output                                qcb2tcb_hld;
  output                                qcb2tcb_vld;
  output                                qmc2qpc_enq;
  output                                qmc2qpc_deq;
  output                                qmc2qrc_enq;
  output                                qmc2qrc_deq;
  output                                qmc2qvc_enq;
  output                                qmc2qvc_deq;

// ----------------------------------------------------------------------------
// Variables
// ----------------------------------------------------------------------------
  wire [`FIRE_DBG_DATA_BITS]            qcb2csr_dbg_a, qcb2csr_dbg_b;

  reg                                   qcb2orb_enq;
  reg                                   qcb2tcb_hld;
  reg                                   deq, nxt_deq;

  reg  [`FIRE_DLC_MMU_CSR_DS_BITS]      dbg_sel [0:1];
  reg  [`FIRE_DBG_DATA_BITS]            dbg_bus [0:1];

  integer i;

// ----------------------------------------------------------------------------
// Combinational
// ----------------------------------------------------------------------------
  wire   qcb2csr_paq = qpc2qmc_vld[0];
  wire   qcb2csr_vaq = qvc2qmc_vld[0];

  wire   vaq_full = qvc2qmc_vld[`FIRE_DLC_MMU_VAQ_DPTH-2];
  wire   rdq_full = qrc2qmc_vld[`FIRE_DLC_MMU_RDQ_DPTH-2];

  wire   qcb2irb_full = vaq_full | rdq_full;

  wire   enq = tcb2qcb_vld[`FIRE_DLC_MMU_PLS_DPTH];

  always @ (orb2qcb_full or qpc2qmc_vld or enq or deq) begin
    case ({enq, deq}) // synopsys parallel_case
      2'b00 : nxt_deq = qpc2qmc_vld[0] & ~orb2qcb_full;
      2'b01 : nxt_deq = qpc2qmc_vld[1] & ~orb2qcb_full;
      2'b10 : nxt_deq = ~orb2qcb_full;
      2'b11 : nxt_deq = ~orb2qcb_full;
    endcase
  end

  always @ (orb2qcb_full or tcb2qcb_vld or qpc2qmc_vld ) begin
    if (!orb2qcb_full) begin
      qcb2tcb_hld = 1'b0;
    end
    else begin
      case (tcb2qcb_vld) // synopsys parallel_case
        3'b000 : qcb2tcb_hld = 1'b0;
        3'b001 : qcb2tcb_hld = qpc2qmc_vld[3];
        3'b010 : qcb2tcb_hld = qpc2qmc_vld[3];
        3'b011 : qcb2tcb_hld = qpc2qmc_vld[2];
        3'b100 : qcb2tcb_hld = qpc2qmc_vld[3];
        3'b101 : qcb2tcb_hld = qpc2qmc_vld[2];
        3'b110 : qcb2tcb_hld = qpc2qmc_vld[2];
        3'b111 : qcb2tcb_hld = qpc2qmc_vld[1];
      endcase
    end
  end

  wire   qcb2tcb_vld = qvc2qmc_vld[0];

  wire   qmc2qpc_enq = enq;

  wire   qmc2qrc_enq = irb2qcb_enq;
  wire   qmc2qvc_enq = irb2qcb_enq;

  wire   qmc2qpc_deq = deq;
  wire   qmc2qrc_deq = deq;

  wire   qmc2qvc_deq = qvc2qmc_vld[0] & ~tcb2qcb_hld;

// ----------------------------------------------------------------------------
// Debug
// ----------------------------------------------------------------------------
  always @ (csr2qcb_ds_a or csr2qcb_ds_b) begin
    dbg_sel[0] = csr2qcb_ds_a;
    dbg_sel[1] = csr2qcb_ds_b;
  end

  assign qcb2csr_dbg_a = dbg_bus[0];
  assign qcb2csr_dbg_b = dbg_bus[1];

// ----------------------------------------------------------------------------
// Sequential
// ----------------------------------------------------------------------------
  always @ (posedge clk) begin
    if (!rst_l) begin
      qcb2orb_enq <= 0;
      deq         <= 0;
    end
    else begin
      qcb2orb_enq <= nxt_deq;
      deq         <= nxt_deq;
    end
  end

  always @ (posedge clk)
        if(~rst_l) begin : dbg_rst
           integer j;
    for (j = 0; j < 2; j = j + 1) begin
        dbg_bus[j] <= 8'h00;
        end
      end
        else begin
    for (i = 0; i < 2; i = i + 1) begin
      case (dbg_sel[i]) // synopsys infer_mux
        3'b000: dbg_bus[i] <= { qpc2qmc_vld, qvc2qmc_vld };
        3'b001: dbg_bus[i] <= qrc2qmc_vld;
        3'b010: dbg_bus[i] <= 8'h00;
        3'b011: dbg_bus[i] <= 8'h00;
        3'b100: dbg_bus[i] <= 8'h00;
        3'b101: dbg_bus[i] <= 8'h00;
        3'b110: dbg_bus[i] <= 8'h00;
        3'b111: dbg_bus[i] <= 8'h00;
      endcase
    end
  end

endmodule // dmu_mmu_qcb_qmc