first cut at gpmc <-> wb bridge, split u1e into core, top, and tb

6 files changed, 159 insertions, 34 deletions

diff --git a/usrp2/gpmc/gpmc.v b/usrp2/gpmc/gpmc.v
new file mode 100644
index 000000000..96ee139fd
--- /dev/null
+++ b/usrp2/gpmc/gpmc.v
@@ -0,0 +1,66 @@
+`timescale 1ns / 1ps
+//////////////////////////////////////////////////////////////////////////////////
+
+module gpmc
+  (input EM_CLK, inout [15:0] EM_D, input [10:1] EM_A, input [1:0] EM_NBE,
+   input EM_WAIT0, input EM_NCS4, input EM_NCS6, input EM_NWE, input EM_NOE,
+
+   input wb_clk, input wb_rst,
+   output reg [10:0] wb_adr_o, output reg [15:0] wb_dat_mosi, input [15:0] wb_dat_miso,
+   output reg [1:0] wb_sel_o, output wb_cyc_o, output reg wb_stb_o, output reg wb_we_o, input wb_ack_i
+   );
+
+   wire 	EM_output_enable = (~EM_NOE & (~EM_NCS4 | ~EM_NCS6));
+   wire [15:0] 	EM_D_ram;
+   reg [15:0] 	EM_D_wb;
+
+   assign EM_D = ~EM_output_enable ? 16'bz : ~EM_NCS4 ? EM_D_ram : EM_D_wb;
+
+   // CS4 is RAM_2PORT for high-speed data
+   ram_2port #(.DWIDTH(16), .AWIDTH(10)) ram_2port
+     (.clka(clk_fpga), .ena(~EM_NCS4), .wea(~EM_NWE), .addra(EM_A), .dia(EM_D), .doa(EM_D_ram),
+      .clkb(clk_fpga), .enb(0), .web(0), .addrb(0), .dib(0), .dob());
+
+   // CS6 is Control, Wishbone bus bridge (wb master)
+   // Sync version
+   reg [1:0] 	cs_del, we_del, oe_del;
+
+   // Synchronize the async control signals
+   always @(posedge wb_clk)
+     begin
+	cs_del <= { cs_del[0], EM_NCS6 };
+	we_del <= { we_del[0], EM_NWE };
+	oe_del <= { oe_del[0], EM_NOE };
+     end
+
+   always @(posedge wb_clk)
+     if(cs_del == 2'b10)  // Falling Edge
+       wb_adr_o <= { EM_A, 1'b0 };
+
+   always @(posedge wb_clk)
+     if(we_del == 2'b10)  // Falling Edge
+       begin
+	  wb_dat_mosi <= EM_D;
+	  wb_sel_o <= ~EM_NBE;
+       end
+
+   always @(posedge wb_clk)
+     if(wb_ack_i)
+       EM_D_wb <= wb_dat_miso;
+
+   // stb, oe_del, we_del
+   assign wb_cyc_o = wb_stb_o;
+
+   always @(posedge wb_clk)
+     if( ~cs_del[0] & (we_del == 2'b10) )
+       wb_we_o <= 1;
+     else if(wb_ack_i)  // Turn off we when done.  Could also use we_del[0], others...
+       wb_we_o <= 0;
+
+   always @(posedge wb_clk)
+     if( ~cs_del[0] & ((we_del == 2'b10) | (oe_del == 2'b10)))
+       wb_stb_o <= 1;
+     else if(wb_ack_i)
+       wb_stb_o <= 0;
+   
+endmodule // gpmc
diff --git a/usrp2/top/u1e/Makefile b/usrp2/top/u1e/Makefile
index e9c101226..cdbdf995e 100644
--- a/usrp2/top/u1e/Makefile
+++ b/usrp2/top/u1e/Makefile
@@ -174,7 +174,8 @@ timing/time_receiver.v \
 timing/time_sender.v \
 timing/time_sync.v \
 timing/timer.v \
-top/u2_core/u2_core.v \
+gpmc/gpmc.v \
+top/u1e/u1e_core.v \
 top/u1e/u1e.ucf \
 top/u1e/u1e.v 
 
diff --git a/usrp2/top/u1e/tb_u1e.v b/usrp2/top/u1e/tb_u1e.v
new file mode 100644
index 000000000..6e0c60e17
--- /dev/null
+++ b/usrp2/top/u1e/tb_u1e.v
@@ -0,0 +1,25 @@
+`timescale 1ns / 1ps
+//////////////////////////////////////////////////////////////////////////////////
+
+module tb_u1e();
+   
+   wire [2:0] debug_led;
+   wire [31:0] debug;
+   wire [1:0] debug_clk;
+   
+   
+   // GPMC
+   wire       EM_CLK, EM_WAIT0, EM_NCS4, EM_NCS6, EM_NWE, EM_NOE;
+   wire [15:0] EM_D;
+   wire [10:1] EM_A;
+   wire [1:0]  EM_NBE;
+   
+   reg  clk_fpga = 0;
+   always #100 clk_fpga = ~clk_fpga;
+   
+   u1e_core u1e_core(.clk_fpga(clk_fpga), .debug_led(debug_led), .debug(debug), .debug_clk(debug_clk),
+		     .EM_CLK(EM_CLK), .EM_D(EM_D), .EM_A(EM_A), .EM_NBE(EM_NBE),
+		     .EM_WAIT0(EM_WAIT0), .EM_NCS4(EM_NCS4), .EM_NCS6(EM_NCS6), 
+		     .EM_NWE(EM_NWE), .EM_NOE(EM_NOE) );
+   
+endmodule // u1e
diff --git a/usrp2/top/u1e/u1e.ucf b/usrp2/top/u1e/u1e.ucf
index cb6d6372e..3b524a6ea 100644
--- a/usrp2/top/u1e/u1e.ucf
+++ b/usrp2/top/u1e/u1e.ucf
@@ -3,8 +3,6 @@ NET "CLK_FPGA_P"  LOC = "Y11"  ;
 NET "CLK_FPGA_N"  LOC = "Y10"  ;
 
 ## GPMC
-NET "EM_CLK"  LOC = "F11"  ;
-
 NET "EM_D<15>"  LOC = "D13"  ;
 NET "EM_D<14>"  LOC = "D15"  ;
 NET "EM_D<13>"  LOC = "C16"  ;
@@ -33,20 +31,20 @@ NET "EM_A<3>"  LOC = "E7"  ;
 NET "EM_A<2>"  LOC = "A7"  ;
 NET "EM_A<1>"  LOC = "C15"  ;
 
-#NET "EM_NCS6"  LOC = "E17"  ;
+NET "EM_NCS6"  LOC = "E17"  ;
 #NET "EM_NCS5"  LOC = "E10"  ;
 NET "EM_NCS4"  LOC = "E6"  ;
 #NET "EM_NCS1"  LOC = "D18"  ;
 #NET "EM_NCS0"  LOC = "D17"  ;
 
+NET "EM_CLK"  LOC = "F11"  ;
 NET "EM_WAIT0"  LOC = "F14"  ;
-#NET "EM_NBE1"  LOC = "D14"  ;
-#NET "EM_NBE0"  LOC = "A13"  ;
-NET "EM_NWP"  LOC = "F13"  ;
+NET "EM_NBE<1>"  LOC = "D14"  ;
+NET "EM_NBE<0>"  LOC = "A13"  ;
 NET "EM_NWE"  LOC = "B13"  ;
 NET "EM_NOE"  LOC = "A14"  ;
-NET "EM_NADV_ALE"  LOC = "B15"  ;
-
+#NET "EM_NADV_ALE"  LOC = "B15"  ;
+#NET "EM_NWP"  LOC = "F13"  ;
 
 ## Overo GPIO
 #NET "overo_gpio0"  LOC = "F9"  ;
diff --git a/usrp2/top/u1e/u1e.v b/usrp2/top/u1e/u1e.v
index e28a6a582..8832d6e11 100644
--- a/usrp2/top/u1e/u1e.v
+++ b/usrp2/top/u1e/u1e.v
@@ -2,13 +2,12 @@
 //////////////////////////////////////////////////////////////////////////////////
 
 module u1e
-  (
-   input CLK_FPGA_P, input CLK_FPGA_N,  // Diff
+  (input CLK_FPGA_P, input CLK_FPGA_N,  // Diff
    output [2:0] debug_led, output [31:0] debug, output [1:0] debug_clk,
 
    // GPMC
-   input EM_CLK, inout [15:0] EM_D, input [10:1] EM_A,
-   input EM_WAIT0, input EM_NCS4, input EM_NWP, input EM_NWE, input EM_NOE, input EM_NADV_ALE
+   input EM_CLK, inout [15:0] EM_D, input [10:1] EM_A, input [1:0] EM_NBE,
+   input EM_WAIT0, input EM_NCS4, input EM_NCS6, input EM_NWE, input EM_NOE
    );
 
    // FPGA-specific pins connections
@@ -17,25 +16,9 @@ module u1e
    IBUFGDS #(.IOSTANDARD("LVDS_33"), .DIFF_TERM("TRUE")) 
    clk_fpga_pin (.O(clk_fpga),.I(CLK_FPGA_P),.IB(CLK_FPGA_N));
 
-   // Debug circuitry
-   reg [31:0] 	ctr;
-   always @(posedge clk_fpga)
-     ctr <= ctr + 1;
-
-   
-   assign debug_led = ctr[27:25];
-   assign debug_clk = { EM_CLK, clk_fpga };
-   assign debug = { { EM_WAIT0, EM_NADV_ALE, EM_NWP, EM_NCS4, EM_NWE, EM_NOE, EM_A[10:1] },
-		    { EM_D } };
-
-   wire 	EM_output_enable = (~EM_NOE & ~EM_NCS4);
-   wire [15:0] 	EM_D_out;
-
-   assign EM_D = EM_output_enable ? EM_D_out : 16'bz;
-
-   ram_2port #(.DWIDTH(16), .AWIDTH(10)) ram_2port
-     (.clka(clk_fpga), .ena(~EM_NCS4), .wea(~EM_NWE), .addra(EM_A), .dia(EM_D), .doa(EM_D_out),
-      .clkb(clk_fpga), .enb(0), .web(0), .addrb(0), .dib(0), .dob());
+   u1e_core u1e_core(.clk_fpga(clk_fpga), .debug_led(debug_led), .debug(debug), .debug_clk(debug_clk),
+		     .EM_CLK(EM_CLK), .EM_D(EM_D), .EM_A(EM_A), .EM_NBE(EM_NBE),
+		     .EM_WAIT0(EM_WAIT0), .EM_NCS4(EM_NCS4), .EM_NCS6(EM_NCS6), 
+		     .EM_NWE(EM_NWE), .EM_NOE(EM_NOE) );
    
-      
-endmodule // u2plus
+endmodule // u1e
diff --git a/usrp2/top/u1e/u1e_core.v b/usrp2/top/u1e/u1e_core.v
new file mode 100644
index 000000000..2481549b2
--- /dev/null
+++ b/usrp2/top/u1e/u1e_core.v
@@ -0,0 +1,52 @@
+`timescale 1ns / 1ps
+//////////////////////////////////////////////////////////////////////////////////
+
+module u1e_core
+  (input clk_fpga, output [2:0] debug_led, output [31:0] debug, output [1:0] debug_clk,
+
+   // GPMC
+   input EM_CLK, inout [15:0] EM_D, input [10:1] EM_A, input [1:0] EM_NBE,
+   input EM_WAIT0, input EM_NCS4, input EM_NCS6, input EM_NWE, input EM_NOE
+   );
+
+   // Debug circuitry
+   reg [31:0] 	ctr;
+   always @(posedge clk_fpga)
+     ctr <= ctr + 1;
+   
+   assign debug_led = ctr[27:25];
+   assign debug_clk = { EM_CLK, clk_fpga };
+   assign debug = { { 1'b0, EM_WAIT0, EM_NCS6, EM_NCS4, EM_NWE, EM_NOE, EM_A[10:1] },
+		    { EM_D } };
+
+   wire 	wb_clk, wb_rst;
+   wire 	wb_cyc, wb_stb, wb_we, wb_ack;
+   wire [1:0] 	wb_sel;
+   wire [10:0] 	wb_adr;
+   wire [15:0] 	wb_dat_mosi, wb_dat_miso;
+   
+   gpmc gpmc (.EM_CLK(EM_CLK), .EM_D(EM_D), .EM_A(EM_A), .EM_NBE(EM_NBE),
+	      .EM_WAIT0(EM_WAIT0), .EM_NCS4(EM_NCS4), .EM_NCS6(EM_NCS6), .EM_NWE(EM_NWE), 
+	      .EM_NOE(EM_NOE),
+
+	      .wb_clk(wb_clk), .wb_rst(wb_rst),
+	      .wb_adr_o(wb_adr), .wb_dat_mosi(wb_dat_mosi), .wb_dat_miso(wb_dat_miso),
+	      .wb_sel_o(wb_sel), .wb_cyc_o(wb_cyc), .wb_stb_o(wb_stb), .wb_we_o(wb_we),
+	      .wb_ack_i(wb_ack));
+
+   assign wb_clk = clk_fpga;
+   reg [15:0] 	reg_fast, reg_slow;
+
+   localparam [10:0] WB_ADR_REG_FAST = 36;
+   localparam [10:0] WB_ADR_REG_SLOW = 38;
+   
+   always @(posedge wb_clk)
+     if(wb_cyc & wb_stb & wb_we & (wb_adr == WB_ADR_REG_FAST))
+       reg_fast <= wb_dat_mosi;
+
+   assign wb_dat_miso = (wb_adr == WB_ADR_REG_FAST) ? reg_fast : 16'bx;
+
+   assign wb_ack = wb_stb & wb_cyc;
+   
+   
+endmodule // u2plus