// // Generated by Bluespec Compiler, version 2009.11.beta2 (build 18693, 2009-11-24) // // On Tue Jun 8 18:41:53 EDT 2010 // // // Ports: // Name I/O size props // RDY_iport0_put O 1 // RDY_iport1_put O 1 // oport_get O 153 // RDY_oport_get O 1 // CLK I 1 clock // RST_N I 1 reset // iport0_put I 153 // iport1_put I 153 // EN_iport0_put I 1 // EN_iport1_put I 1 // EN_oport_get I 1 // // No combinational paths from inputs to outputs // // module mkPktMerge(CLK, RST_N, iport0_put, EN_iport0_put, RDY_iport0_put, iport1_put, EN_iport1_put, RDY_iport1_put, EN_oport_get, oport_get, RDY_oport_get); input CLK; input RST_N; // action method iport0_put input [152 : 0] iport0_put; input EN_iport0_put; output RDY_iport0_put; // action method iport1_put input [152 : 0] iport1_put; input EN_iport1_put; output RDY_iport1_put; // actionvalue method oport_get input EN_oport_get; output [152 : 0] oport_get; output RDY_oport_get; // signals for module outputs wire [152 : 0] oport_get; wire RDY_iport0_put, RDY_iport1_put, RDY_oport_get; // register fi0Active reg fi0Active; wire fi0Active__D_IN; wire fi0Active__EN; // register fi0HasPrio reg fi0HasPrio; reg fi0HasPrio__D_IN; wire fi0HasPrio__EN; // register fi1Active reg fi1Active; wire fi1Active__D_IN, fi1Active__EN; // ports of submodule fi0 wire [152 : 0] fi0__D_IN, fi0__D_OUT; wire fi0__CLR, fi0__DEQ, fi0__EMPTY_N, fi0__ENQ, fi0__FULL_N; // ports of submodule fi1 wire [152 : 0] fi1__D_IN, fi1__D_OUT; wire fi1__CLR, fi1__DEQ, fi1__EMPTY_N, fi1__ENQ, fi1__FULL_N; // ports of submodule fo reg [152 : 0] fo__D_IN; wire [152 : 0] fo__D_OUT; wire fo__CLR, fo__DEQ, fo__EMPTY_N, fo__ENQ, fo__FULL_N; // rule scheduling signals wire CAN_FIRE_RL_arbitrate, CAN_FIRE_RL_fi0_advance, CAN_FIRE_RL_fi1_advance, CAN_FIRE_iport0_put, CAN_FIRE_iport1_put, CAN_FIRE_oport_get, WILL_FIRE_RL_arbitrate, WILL_FIRE_RL_fi0_advance, WILL_FIRE_RL_fi1_advance, WILL_FIRE_iport0_put, WILL_FIRE_iport1_put, WILL_FIRE_oport_get; // inputs to muxes for submodule ports wire [152 : 0] MUX_fo__enq_1__VAL_1; wire MUX_fi0Active__write_1__SEL_1, MUX_fi0Active__write_1__VAL_1, MUX_fi1Active__write_1__SEL_1; // remaining internal signals reg [63 : 0] v__h679; wire fo_RDY_enq_AND_IF_fi0HasPrio_THEN_fi0_RDY_firs_ETC___d10; // action method iport0_put assign RDY_iport0_put = fi0__FULL_N ; assign CAN_FIRE_iport0_put = fi0__FULL_N ; assign WILL_FIRE_iport0_put = EN_iport0_put ; // action method iport1_put assign RDY_iport1_put = fi1__FULL_N ; assign CAN_FIRE_iport1_put = fi1__FULL_N ; assign WILL_FIRE_iport1_put = EN_iport1_put ; // actionvalue method oport_get assign oport_get = fo__D_OUT ; assign RDY_oport_get = fo__EMPTY_N ; assign CAN_FIRE_oport_get = fo__EMPTY_N ; assign WILL_FIRE_oport_get = EN_oport_get ; // submodule fi0 arSRLFIFO_a fi0 (.CLK(CLK), .RST_N(RST_N), .D_IN(fi0__D_IN), .ENQ(fi0__ENQ), .DEQ(fi0__DEQ), .CLR(fi0__CLR), .D_OUT(fi0__D_OUT), .EMPTY_N(fi0__EMPTY_N), .FULL_N(fi0__FULL_N)); // submodule fi1 arSRLFIFO_b fi1 (.CLK(CLK), .RST_N(RST_N), .D_IN(fi1__D_IN), .ENQ(fi1__ENQ), .DEQ(fi1__DEQ), .CLR(fi1__CLR), .D_OUT(fi1__D_OUT), .EMPTY_N(fi1__EMPTY_N), .FULL_N(fi1__FULL_N)); // submodule fo arSRLFIFO_c fo (.CLK(CLK), .RST_N(RST_N), .D_IN(fo__D_IN), .ENQ(fo__ENQ), .DEQ(fo__DEQ), .CLR(fo__CLR), .D_OUT(fo__D_OUT), .EMPTY_N(fo__EMPTY_N), .FULL_N(fo__FULL_N)); // rule RL_arbitrate assign CAN_FIRE_RL_arbitrate = fo_RDY_enq_AND_IF_fi0HasPrio_THEN_fi0_RDY_firs_ETC___d10 && fi0__EMPTY_N && fi1__EMPTY_N && !fi0Active && !fi1Active ; assign WILL_FIRE_RL_arbitrate = CAN_FIRE_RL_arbitrate ; // rule RL_fi0_advance assign CAN_FIRE_RL_fi0_advance = fi0__EMPTY_N && fo__FULL_N && !fi1Active ; assign WILL_FIRE_RL_fi0_advance = CAN_FIRE_RL_fi0_advance && !WILL_FIRE_RL_arbitrate ; // rule RL_fi1_advance assign CAN_FIRE_RL_fi1_advance = fi1__EMPTY_N && fo__FULL_N && !fi0Active ; assign WILL_FIRE_RL_fi1_advance = CAN_FIRE_RL_fi1_advance && !WILL_FIRE_RL_fi0_advance && !WILL_FIRE_RL_arbitrate ; // inputs to muxes for submodule ports assign MUX_fi0Active__write_1__SEL_1 = WILL_FIRE_RL_arbitrate && fi0HasPrio ; assign MUX_fi1Active__write_1__SEL_1 = WILL_FIRE_RL_arbitrate && !fi0HasPrio ; assign MUX_fi0Active__write_1__VAL_1 = fi0HasPrio ? !fi0__D_OUT[151] : !fi1__D_OUT[151] ; assign MUX_fo__enq_1__VAL_1 = fi0HasPrio ? fi0__D_OUT : fi1__D_OUT ; // register fi0Active assign fi0Active__D_IN = MUX_fi0Active__write_1__SEL_1 ? MUX_fi0Active__write_1__VAL_1 : !fi0__D_OUT[151] ; assign fi0Active__EN = WILL_FIRE_RL_arbitrate && fi0HasPrio || WILL_FIRE_RL_fi0_advance ; // register fi0HasPrio always@(WILL_FIRE_RL_arbitrate or fi0HasPrio or WILL_FIRE_RL_fi0_advance or WILL_FIRE_RL_fi1_advance) begin // case (1'b1) // synopsys parallel_case // WILL_FIRE_RL_arbitrate: fi0HasPrio__D_IN = !fi0HasPrio; // WILL_FIRE_RL_fi0_advance: fi0HasPrio__D_IN = 1'd0; // WILL_FIRE_RL_fi1_advance: fi0HasPrio__D_IN = 1'd1; //case (1'b1) // synopsys parallel_case // WILL_FIRE_RL_arbitrate: fi0HasPrio__D_IN = !fi0HasPrio; fi0HasPrio__D_IN = !fi0HasPrio; // WILL_FIRE_RL_fi0_advance: fi0HasPrio__D_IN = 1'd0; // WILL_FIRE_RL_fi1_advance: fi0HasPrio__D_IN = 1'd1; // endcase //endcase end assign fi0HasPrio__EN = WILL_FIRE_RL_arbitrate || WILL_FIRE_RL_fi0_advance || WILL_FIRE_RL_fi1_advance ; // register fi1Active assign fi1Active__D_IN = MUX_fi1Active__write_1__SEL_1 ? MUX_fi0Active__write_1__VAL_1 : !fi1__D_OUT[151] ; assign fi1Active__EN = WILL_FIRE_RL_arbitrate && !fi0HasPrio || WILL_FIRE_RL_fi1_advance ; // submodule fi0 assign fi0__D_IN = iport0_put ; assign fi0__DEQ = WILL_FIRE_RL_arbitrate && fi0HasPrio || WILL_FIRE_RL_fi0_advance ; assign fi0__ENQ = EN_iport0_put ; assign fi0__CLR = 1'b0 ; // submodule fi1 assign fi1__D_IN = iport1_put ; assign fi1__DEQ = WILL_FIRE_RL_arbitrate && !fi0HasPrio || WILL_FIRE_RL_fi1_advance ; assign fi1__ENQ = EN_iport1_put ; assign fi1__CLR = 1'b0 ; // submodule fo always@(WILL_FIRE_RL_arbitrate or MUX_fo__enq_1__VAL_1 or WILL_FIRE_RL_fi0_advance or fi0__D_OUT or WILL_FIRE_RL_fi1_advance or fi1__D_OUT) begin // case (1'b1) // synopsys parallel_case //WILL_FIRE_RL_arbitrate: fo__D_IN = MUX_fo__enq_1__VAL_1; fo__D_IN = MUX_fo__enq_1__VAL_1; // WILL_FIRE_RL_fi0_advance: fo__D_IN = fi0__D_OUT; // WILL_FIRE_RL_fi1_advance: fo__D_IN = fi1__D_OUT; // endcase end assign fo__DEQ = EN_oport_get ; assign fo__ENQ = WILL_FIRE_RL_arbitrate || WILL_FIRE_RL_fi0_advance || WILL_FIRE_RL_fi1_advance ; assign fo__CLR = 1'b0 ; // remaining internal signals assign fo_RDY_enq_AND_IF_fi0HasPrio_THEN_fi0_RDY_firs_ETC___d10 = fo__FULL_N && (fi0HasPrio ? fi0__EMPTY_N : fi1__EMPTY_N) ; // handling of inlined registers always@(posedge CLK) begin if (!RST_N) begin fi0Active <= 1'd0; fi0HasPrio <= 1'd1; fi1Active <= 1'd0; end else begin if (fi0Active__EN) fi0Active <= fi0Active__D_IN; if (fi0HasPrio__EN) fi0HasPrio <= fi0HasPrio__D_IN; if (fi1Active__EN) fi1Active <= fi1Active__D_IN; end end // handling of system tasks endmodule // mkPktMerge module arSRLFIFO_a (CLK, RST_N, D_IN,ENQ,DEQ,CLR,D_OUT,EMPTY_N,FULL_N); input CLK; input RST_N; input [152:0] D_IN; input ENQ; input DEQ; input CLR; output [152:0] D_OUT; output EMPTY_N; output FULL_N; wire fulln; wire emptyn; wire always_one; wire always_zero; assign always_one = 1'b1; assign always_zero = 1'b0; generic_fifo_sc_a fifo_1 (.clk(CLK), .rst(RST_N), .clr (CLR), .din (D_IN), .we (ENQ), .dout (D_OUT), .re (DEQ), .full_r (FULL_N), .empty_r(EMPTY_N), .full_n_r (fulln), .empty_n_r (emptyn) ); endmodule ///////////////////////////////////////////////////////////////////// //// //// //// Universal FIFO Single Clock //// //// //// //// //// //// Author: Rudolf Usselmann //// //// rudi@asics.ws //// //// //// //// //// //// D/L from: http://www.opencores.org/cores/generic_fifos/ //// //// //// ///////////////////////////////////////////////////////////////////// //// //// //// Copyright (C) 2000-2002 Rudolf Usselmann //// //// www.asics.ws //// //// rudi@asics.ws //// //// //// //// This source file may be used and distributed without //// //// restriction provided that this copyright statement is not //// //// removed from the file and that any derivative work contains //// //// the original copyright notice and the associated disclaimer.//// //// //// //// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY //// //// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED //// //// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS //// //// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR //// //// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, //// //// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES //// //// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE //// //// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR //// //// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF //// //// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT //// //// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT //// //// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE //// //// POSSIBILITY OF SUCH DAMAGE. //// //// //// ///////////////////////////////////////////////////////////////////// // CVS Log // // __Id: generic_fifo_sc_a.v,v 1.1.1.1 2002-09-25 05:42:06 rudi Exp __ // // __Date: 2002-09-25 05:42:06 __ // __Revision: 1.1.1.1 __ // __Author: rudi __ // __Locker: __ // __State: Exp __ // // Change History: // __Log: not supported by cvs2svn __ // // // // // // // // // // /* Description =========== I/Os ---- rst low active, either sync. or async. master reset (see below how to select) clr synchronous clear (just like reset but always synchronous), high active re read enable, synchronous, high active we read enable, synchronous, high active din Data Input dout Data Output full Indicates the FIFO is full (combinatorial output) full_r same as above, but registered output (see note below) empty Indicates the FIFO is empty empty_r same as above, but registered output (see note below) full_n Indicates if the FIFO has space for N entries (combinatorial output) full_n_r same as above, but registered output (see note below) empty_n Indicates the FIFO has at least N entries (combinatorial output) empty_n_r same as above, but registered output (see note below) level indicates the FIFO level: 2'b00 0-25% full 2'b01 25-50% full 2'b10 50-75% full 2'b11 %75-100% full combinatorial vs. registered status outputs ------------------------------------------- Both the combinatorial and registered status outputs have exactly the same synchronous timing. Meaning they are being asserted immediately at the clock edge after the last read or write. The combinatorial outputs however, pass through several levels of logic before they are output. The registered status outputs are direct outputs of a flip-flop. The reason both are provided, is that the registered outputs require quite a bit of additional logic inside the FIFO. If you can meet timing of your device with the combinatorial outputs, use them ! The FIFO will be smaller. If the status signals are in the critical pass, use the registered outputs, they have a much smaller output delay (actually only Tcq). Parameters ---------- The FIFO takes 3 parameters: dw Data bus width aw Address bus width (Determines the FIFO size by evaluating 2^aw) n N is a second status threshold constant for full_n and empty_n If you have no need for the second status threshold, do not connect the outputs and the logic should be removed by your synthesis tool. Synthesis Results ----------------- In a Spartan 2e a 8 bit wide, 8 entries deep FIFO, takes 85 LUTs and runs at about 116 MHz (IO insertion disabled). The registered status outputs are valid after 2.1NS, the combinatorial once take out to 6.5 NS to be available. Misc ---- This design assumes you will do appropriate status checking externally. IMPORTANT ! writing while the FIFO is full or reading while the FIFO is empty will place the FIFO in an undefined state. */ // Selecting Sync. or Async Reset // ------------------------------ // Uncomment one of the two lines below. The first line for // synchronous reset, the second for asynchronous reset //`define SC_FIFO_ASYNC_RESET // Uncomment for Syncr. reset //`define SC_FIFO_ASYNC_RESET or negedge rst // Uncomment for Async. reset `define dw 153 `define aw 4 `define n 32 `define max_size 30 /* parameter dw=8; parameter aw=8; parameter n=32; parameter max_size = 1<= (`n-1) ) && !re) empty_n_r <= 1'b0; else if(re && (cnt <= `n ) && !we) empty_n_r <= 1'b1; end always @(posedge clk ) begin if(!rst) full_n_r <= 1'b0; else if(clr) full_n_r <= 1'b0; else if(we && (cnt >= (`max_size-`n) ) && !re) full_n_r <= 1'b1; else if(re && (cnt <= (`max_size-`n+1)) && !we) full_n_r <= 1'b0; end endmodule module arSRLFIFO_b (CLK, RST_N, D_IN,ENQ,DEQ,CLR,D_OUT,EMPTY_N,FULL_N); input CLK; input RST_N; input [152:0] D_IN; input ENQ; input DEQ; input CLR; output [152:0] D_OUT; output EMPTY_N; output FULL_N; wire fulln; wire emptyn; wire always_one; wire always_zero; assign always_one = 1'b1; assign always_zero = 1'b0; generic_fifo_sc_b fifo_1 (.clk(CLK), .rst(RST_N), .clr (CLR), .din (D_IN), .we (ENQ), .dout (D_OUT), .re (DEQ), .full_r (FULL_N), .empty_r(EMPTY_N), .full_n_r (fulln), .empty_n_r (emptyn) ); endmodule ///////////////////////////////////////////////////////////////////// //// //// //// Universal FIFO Single Clock //// //// //// //// //// //// Author: Rudolf Usselmann //// //// rudi@asics.ws //// //// //// //// //// //// D/L from: http://www.opencores.org/cores/generic_fifos/ //// //// //// ///////////////////////////////////////////////////////////////////// //// //// //// Copyright (C) 2000-2002 Rudolf Usselmann //// //// www.asics.ws //// //// rudi@asics.ws //// //// //// //// This source file may be used and distributed without //// //// restriction provided that this copyright statement is not //// //// removed from the file and that any derivative work contains //// //// the original copyright notice and the associated disclaimer.//// //// //// //// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY //// //// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED //// //// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS //// //// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR //// //// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, //// //// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES //// //// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE //// //// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR //// //// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF //// //// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT //// //// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT //// //// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE //// //// POSSIBILITY OF SUCH DAMAGE. //// //// //// ///////////////////////////////////////////////////////////////////// // CVS Log // // __Id: generic_fifo_sc_a.v,v 1.1.1.1 2002-09-25 05:42:06 rudi Exp __ // // __Date: 2002-09-25 05:42:06 __ // __Revision: 1.1.1.1 __ // __Author: rudi __ // __Locker: __ // __State: Exp __ // // Change History: // __Log: not supported by cvs2svn __ // // // // // // // // // // /* Description =========== I/Os ---- rst low active, either sync. or async. master reset (see below how to select) clr synchronous clear (just like reset but always synchronous), high active re read enable, synchronous, high active we read enable, synchronous, high active din Data Input dout Data Output full Indicates the FIFO is full (combinatorial output) full_r same as above, but registered output (see note below) empty Indicates the FIFO is empty empty_r same as above, but registered output (see note below) full_n Indicates if the FIFO has space for N entries (combinatorial output) full_n_r same as above, but registered output (see note below) empty_n Indicates the FIFO has at least N entries (combinatorial output) empty_n_r same as above, but registered output (see note below) level indicates the FIFO level: 2'b00 0-25% full 2'b01 25-50% full 2'b10 50-75% full 2'b11 %75-100% full combinatorial vs. registered status outputs ------------------------------------------- Both the combinatorial and registered status outputs have exactly the same synchronous timing. Meaning they are being asserted immediately at the clock edge after the last read or write. The combinatorial outputs however, pass through several levels of logic before they are output. The registered status outputs are direct outputs of a flip-flop. The reason both are provided, is that the registered outputs require quite a bit of additional logic inside the FIFO. If you can meet timing of your device with the combinatorial outputs, use them ! The FIFO will be smaller. If the status signals are in the critical pass, use the registered outputs, they have a much smaller output delay (actually only Tcq). Parameters ---------- The FIFO takes 3 parameters: dw Data bus width aw Address bus width (Determines the FIFO size by evaluating 2^aw) n N is a second status threshold constant for full_n and empty_n If you have no need for the second status threshold, do not connect the outputs and the logic should be removed by your synthesis tool. Synthesis Results ----------------- In a Spartan 2e a 8 bit wide, 8 entries deep FIFO, takes 85 LUTs and runs at about 116 MHz (IO insertion disabled). The registered status outputs are valid after 2.1NS, the combinatorial once take out to 6.5 NS to be available. Misc ---- This design assumes you will do appropriate status checking externally. IMPORTANT ! writing while the FIFO is full or reading while the FIFO is empty will place the FIFO in an undefined state. */ // Selecting Sync. or Async Reset // ------------------------------ // Uncomment one of the two lines below. The first line for // synchronous reset, the second for asynchronous reset //`define SC_FIFO_ASYNC_RESET // Uncomment for Syncr. reset //`define SC_FIFO_ASYNC_RESET or negedge rst // Uncomment for Async. reset /* parameter dw=8; parameter aw=8; parameter n=32; parameter max_size = 1<= (`n-1) ) && !re) empty_n_r <= 1'b0; else if(re && (cnt <= `n ) && !we) empty_n_r <= 1'b1; end always @(posedge clk ) begin if(!rst) full_n_r <= 1'b0; else if(clr) full_n_r <= 1'b0; else if(we && (cnt >= (`max_size-`n) ) && !re) full_n_r <= 1'b1; else if(re && (cnt <= (`max_size-`n+1)) && !we) full_n_r <= 1'b0; end endmodule module arSRLFIFO_c (CLK, RST_N, D_IN,ENQ,DEQ,CLR,D_OUT,EMPTY_N,FULL_N); input CLK; input RST_N; input [152:0] D_IN; input ENQ; input DEQ; input CLR; output [152:0] D_OUT; output EMPTY_N; output FULL_N; wire fulln; wire emptyn; wire always_one; wire always_zero; assign always_one = 1'b1; assign always_zero = 1'b0; generic_fifo_sc_c fifo_1 (.clk(CLK), .rst(RST_N), .clr (CLR), .din (D_IN), .we (ENQ), .dout (D_OUT), .re (DEQ), .full_r (FULL_N), .empty_r(EMPTY_N), .full_n_r (fulln), .empty_n_r (emptyn) ); endmodule ///////////////////////////////////////////////////////////////////// //// //// //// Universal FIFO Single Clock //// //// //// //// //// //// Author: Rudolf Usselmann //// //// rudi@asics.ws //// //// //// //// //// //// D/L from: http://www.opencores.org/cores/generic_fifos/ //// //// //// ///////////////////////////////////////////////////////////////////// //// //// //// Copyright (C) 2000-2002 Rudolf Usselmann //// //// www.asics.ws //// //// rudi@asics.ws //// //// //// //// This source file may be used and distributed without //// //// restriction provided that this copyright statement is not //// //// removed from the file and that any derivative work contains //// //// the original copyright notice and the associated disclaimer.//// //// //// //// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY //// //// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED //// //// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS //// //// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR //// //// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, //// //// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES //// //// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE //// //// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR //// //// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF //// //// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT //// //// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT //// //// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE //// //// POSSIBILITY OF SUCH DAMAGE. //// //// //// ///////////////////////////////////////////////////////////////////// // CVS Log // // __Id: generic_fifo_sc_a.v,v 1.1.1.1 2002-09-25 05:42:06 rudi Exp __ // // __Date: 2002-09-25 05:42:06 __ // __Revision: 1.1.1.1 __ // __Author: rudi __ // __Locker: __ // __State: Exp __ // // Change History: // __Log: not supported by cvs2svn __ // // // // // // // // // // /* Description =========== I/Os ---- rst low active, either sync. or async. master reset (see below how to select) clr synchronous clear (just like reset but always synchronous), high active re read enable, synchronous, high active we read enable, synchronous, high active din Data Input dout Data Output full Indicates the FIFO is full (combinatorial output) full_r same as above, but registered output (see note below) empty Indicates the FIFO is empty empty_r same as above, but registered output (see note below) full_n Indicates if the FIFO has space for N entries (combinatorial output) full_n_r same as above, but registered output (see note below) empty_n Indicates the FIFO has at least N entries (combinatorial output) empty_n_r same as above, but registered output (see note below) level indicates the FIFO level: 2'b00 0-25% full 2'b01 25-50% full 2'b10 50-75% full 2'b11 %75-100% full combinatorial vs. registered status outputs ------------------------------------------- Both the combinatorial and registered status outputs have exactly the same synchronous timing. Meaning they are being asserted immediately at the clock edge after the last read or write. The combinatorial outputs however, pass through several levels of logic before they are output. The registered status outputs are direct outputs of a flip-flop. The reason both are provided, is that the registered outputs require quite a bit of additional logic inside the FIFO. If you can meet timing of your device with the combinatorial outputs, use them ! The FIFO will be smaller. If the status signals are in the critical pass, use the registered outputs, they have a much smaller output delay (actually only Tcq). Parameters ---------- The FIFO takes 3 parameters: dw Data bus width aw Address bus width (Determines the FIFO size by evaluating 2^aw) n N is a second status threshold constant for full_n and empty_n If you have no need for the second status threshold, do not connect the outputs and the logic should be removed by your synthesis tool. Synthesis Results ----------------- In a Spartan 2e a 8 bit wide, 8 entries deep FIFO, takes 85 LUTs and runs at about 116 MHz (IO insertion disabled). The registered status outputs are valid after 2.1NS, the combinatorial once take out to 6.5 NS to be available. Misc ---- This design assumes you will do appropriate status checking externally. IMPORTANT ! writing while the FIFO is full or reading while the FIFO is empty will place the FIFO in an undefined state. */ // Selecting Sync. or Async Reset // ------------------------------ // Uncomment one of the two lines below. The first line for // synchronous reset, the second for asynchronous reset //`define SC_FIFO_ASYNC_RESET // Uncomment for Syncr. reset //`define SC_FIFO_ASYNC_RESET or negedge rst // Uncomment for Async. reset /* parameter dw=8; parameter aw=8; parameter n=32; parameter max_size = 1<= (`n-1) ) && !re) empty_n_r <= 1'b0; else if(re && (cnt <= `n ) && !we) empty_n_r <= 1'b1; end always @(posedge clk ) begin if(!rst) full_n_r <= 1'b0; else if(clr) full_n_r <= 1'b0; else if(we && (cnt >= (`max_size-`n) ) && !re) full_n_r <= 1'b1; else if(re && (cnt <= (`max_size-`n+1)) && !we) full_n_r <= 1'b0; end endmodule