module pci_pci_tpram
(
	// Generic synchronous two-port RAM interface
	clk_a,
    rst_a,
    ce_a,
    we_a,
    oe_a,
    addr_a,
    di_a,
    do_a,
	clk_b,
    rst_b,
    ce_b,
    we_b,
    oe_b,
    addr_b,
    di_b,
    do_b
`ifdef PCI_BIST
    ,
    // debug chain signals
    mbist_si_i,       // bist scan serial in
    mbist_so_o,       // bist scan serial out
    mbist_ctrl_i        // bist chain shift control
`endif
);

//
// Default address and data buses width
//
parameter aw = 8;
parameter dw = 40;

//
// Generic synchronous two-port RAM interface
//
input			clk_a;	// Clock
input			rst_a;	// Reset
input			ce_a;	// Chip enable input
input			we_a;	// Write enable input
input			oe_a;	// Output enable input
input 	[aw-1:0]	addr_a;	// address bus inputs
input	[dw-1:0]	di_a;	// input data bus
output	[dw-1:0]	do_a;	// output data bus
input			clk_b;	// Clock
input			rst_b;	// Reset
input			ce_b;	// Chip enable input
input			we_b;	// Write enable input
input			oe_b;	// Output enable input
input 	[aw-1:0]	addr_b;	// address bus inputs
input	[dw-1:0]	di_b;	// input data bus
output	[dw-1:0]	do_b;	// output data bus

`ifdef PCI_BIST
// debug chain signals
input   mbist_si_i;       // bist scan serial in
output  mbist_so_o;       // bist scan serial out
input [`PCI_MBIST_CTRL_WIDTH - 1:0] mbist_ctrl_i;       // bist chain shift control
`endif

//
// Internal wires and registers
//

`ifdef PCI_VS_STP
    `define PCI_PCI_RAM_SELECTED
    `ifdef PCI_BIST
        vs_hdtp_64x40_bist i_vs_hdtp_64x40_bist
    `else
        vs_hdtp_64x40 i_vs_hdtp_64x40
    `endif
        (
            .RCK        (clk_b),
            .WCK        (clk_a),
            .RADR       (addr_b),
            .WADR       (addr_a),
            .DI         (di_a),
            .DOUT       (do_b),
            .REN        (1'b0),
            .WEN        (!we_a)
        `ifdef PCI_BIST
            ,
            // debug chain signals
            .mbist_si_i   (mbist_si_i),
            .mbist_so_o   (mbist_so_o),
            .mbist_ctrl_i   (mbist_ctrl_i)
        `endif
        );

    assign do_a = 0 ;
`endif

`ifdef PCI_ARTISAN_SDP
    `define PCI_PCI_RAM_SELECTED
    //
    // Instantiation of ASIC memory:
    //
    // Artisan Synchronous Double-Port RAM (ra2sh)
    //
    `ifdef PCI_BIST
        art_hsdp_64x40_bist /*#(dw, 1<<aw, aw) */ artisan_sdp
        (
        	.QA(do_a),
        	.CLKA(clk_a),
        	.CENA(~ce_a),
        	.WENA(~we_a),
        	.AA(addr_a),
        	.DA(di_a),
        	.OENA(~oe_a),
        	.QB(do_b),
        	.CLKB(clk_b),
        	.CENB(~ce_b),
        	.WENB(~we_b),
        	.AB(addr_b),
        	.DB(di_b),
        	.OENB(~oe_b),
          .mbist_si_i   (mbist_si_i),
          .mbist_so_o   (mbist_so_o),
          .mbist_ctrl_i   (mbist_ctrl_i)
        );
    `else
        art_hsdp_64x40 /*#(dw, 1<<aw, aw) */ artisan_sdp
        (
        	.QA(do_a),
        	.CLKA(clk_a),
        	.CENA(~ce_a),
        	.WENA(~we_a),
        	.AA(addr_a),
        	.DA(di_a),
        	.OENA(~oe_a),
        	.QB(do_b),
        	.CLKB(clk_b),
        	.CENB(~ce_b),
        	.WENB(~we_b),
        	.AB(addr_b),
        	.DB(di_b),
        	.OENB(~oe_b)
        );
    `endif
`endif

`ifdef AVANT_ATP
    `define PCI_PCI_RAM_SELECTED
    //
    // Instantiation of ASIC memory:
    //
    // Avant! Asynchronous Two-Port RAM
    //
    avant_atp avant_atp(
    	.web(~we),
    	.reb(),
    	.oeb(~oe),
    	.rcsb(),
    	.wcsb(),
    	.ra(addr),
    	.wa(addr),
    	.di(di),
    	.do(do)
    );
`endif

`ifdef VIRAGE_STP
    `define PCI_PCI_RAM_SELECTED
    //
    // Instantiation of ASIC memory:
    //
    // Virage Synchronous 2-port R/W RAM
    //
    virage_stp virage_stp(
    	.QA(do_a),
    	.QB(do_b),

    	.ADRA(addr_a),
    	.DA(di_a),
    	.WEA(we_a),
    	.OEA(oe_a),
    	.MEA(ce_a),
    	.CLKA(clk_a),

    	.ADRB(adr_b),
    	.DB(di_b),
    	.WEB(we_b),
    	.OEB(oe_b),
    	.MEB(ce_b),
    	.CLKB(clk_b)
    );
`endif

`ifdef PCI_XILINX_RAMB4
    `define PCI_PCI_RAM_SELECTED
    //
    // Instantiation of FPGA memory:
    //
    // Virtex/Spartan2
    //

    //
    // Block 0
    //

    RAMB4_S16_S16 ramb4_s16_s16_0(
    	.CLKA(clk_a),
    	.RSTA(rst_a),
    	.ADDRA(addr_a),
    	.DIA(di_a[15:0]),
    	.ENA(ce_a),
    	.WEA(we_a),
    	.DOA(do_a[15:0]),

    	.CLKB(clk_b),
    	.RSTB(rst_b),
    	.ADDRB(addr_b),
    	.DIB(di_b[15:0]),
    	.ENB(ce_b),
    	.WEB(we_b),
    	.DOB(do_b[15:0])
    );

    //
    // Block 1
    //

    RAMB4_S16_S16 ramb4_s16_s16_1(
    	.CLKA(clk_a),
    	.RSTA(rst_a),
    	.ADDRA(addr_a),
    	.DIA(di_a[31:16]),
    	.ENA(ce_a),
    	.WEA(we_a),
    	.DOA(do_a[31:16]),

    	.CLKB(clk_b),
    	.RSTB(rst_b),
    	.ADDRB(addr_b),
    	.DIB(di_b[31:16]),
    	.ENB(ce_b),
    	.WEB(we_b),
    	.DOB(do_b[31:16])
    );

    //
    // Block 2
    //
    // block ram2 wires - non generic width of block rams
    wire [15:0] blk2_di_a = {8'h00, di_a[39:32]} ;
    wire [15:0] blk2_di_b = {8'h00, di_b[39:32]} ;

    wire [15:0] blk2_do_a ;
    wire [15:0] blk2_do_b ;

    assign do_a[39:32] = blk2_do_a[7:0] ;
    assign do_b[39:32] = blk2_do_b[7:0] ;

    RAMB4_S16_S16 ramb4_s16_s16_2(
            .CLKA(clk_a),
            .RSTA(rst_a),
            .ADDRA(addr_a),
            .DIA(blk2_di_a),
            .ENA(ce_a),
            .WEA(we_a),
            .DOA(blk2_do_a),

            .CLKB(clk_b),
            .RSTB(rst_b),
            .ADDRB(addr_b),
            .DIB(blk2_di_b),
            .ENB(ce_b),
            .WEB(we_b),
            .DOB(blk2_do_b)
    );

`endif

`ifdef PCI_XILINX_DIST_RAM
    `define PCI_PCI_RAM_SELECTED
    reg [(aw-1):0] out_address ;
    always@(posedge clk_b or posedge rst_b)
    begin
        if ( rst_b )
            out_address <= #1 0 ;
        else if (ce_b)
            out_address <= #1 addr_b ;
    end

    pci_ram_16x40d #(aw) pci_distributed_ram
    (
        .data_out       (do_b),
        .we             (we_a),
        .data_in        (di_a),
        .read_address   (out_address),
        .write_address  (addr_a),
        .wclk           (clk_a)
    );

    assign do_a = 0 ;
`endif

`ifdef PCI_PCI_RAM_SELECTED
`else
    //
    // Generic two-port synchronous RAM model
    //

    //
    // Generic RAM's registers and wires
    //
    reg	[dw-1:0]	mem [(1<<aw)-1:0];	// RAM content
    reg	[dw-1:0]	do_reg_b;		// RAM data output register

    //
    // Data output drivers
    //
    assign do_a = {dw{1'b0}} ;
    assign do_b = do_reg_b   ;

    //
    // RAM read and write
    //
    always @(posedge clk_a)
    	if (ce_a && we_a)
    		mem[addr_a] <= #1 di_a;

    //
    // RAM read and write
    //
    always @(posedge clk_b)
    	if (ce_b)
    		do_reg_b <= #1 mem[addr_b];
`endif

// synopsys translate_off
initial
begin
    if (dw !== 40)
    begin
        $display("RAM instantiation error! Expected RAM width %d, actual %h!", 40, dw) ;
        $finish ;
    end
    `ifdef XILINX_RAMB4
        if (aw !== 8)
        begin
            $display("RAM instantiation error! Expected RAM address width %d, actual %h!", 40, aw) ;
            $finish ;
        end
    `endif
    // currenlty only artisan ram of depth 256 is supported - they don't provide generic ram models
    `ifdef ARTISAN_SDP
        if (aw !== 8)
        begin
            $display("RAM instantiation error! Expected RAM address width %d, actual %h!", 40, aw) ;
            $finish ;
        end
    `endif
end
// synopsys translate_on

endmodule