removes the icache and pipelines the reads

5 files changed, 98 insertions, 16 deletions

diff --git a/usrp2/control_lib/ram_harvard.v b/usrp2/control_lib/ram_harvard.v
new file mode 100644
index 000000000..6711da366
--- /dev/null
+++ b/usrp2/control_lib/ram_harvard.v
@@ -0,0 +1,71 @@
+
+
+// Dual ported, Harvard architecture, cached ram
+
+module ram_harvard
+  #(parameter AWIDTH=15,
+    parameter RAM_SIZE=16384,
+    parameter ICWIDTH=6,
+    parameter DCWIDTH=6)
+   
+    (input wb_clk_i, 
+     input wb_rst_i,
+     // Firmware download port.
+     input [AWIDTH-1:0] ram_loader_adr_i,
+     input [31:0] ram_loader_dat_i,
+     input ram_loader_stb_i,
+     input [3:0] ram_loader_sel_i,
+     input ram_loader_we_i,
+     output ram_loader_ack_o,
+     input ram_loader_done_i,    
+     // Instruction fetch port.
+     input [AWIDTH-1:0] if_adr,
+     output [31:0] if_data,
+     // Data access port.
+     input [AWIDTH-1:0] dwb_adr_i,
+     input [31:0] dwb_dat_i, 
+     output [31:0] dwb_dat_o,
+     input dwb_we_i,
+     output dwb_ack_o,
+     input dwb_stb_i,
+     input [3:0] dwb_sel_i,
+
+     input flush_icache );
+
+   reg 	   ack_d1;
+   reg 	   stb_d1;
+   
+   
+   dpram32 #(.AWIDTH(AWIDTH),.RAM_SIZE(RAM_SIZE)) 
+   sys_ram
+     (.clk(wb_clk_i),
+      .adr1_i(ram_loader_done_i ? if_adr : ram_loader_adr_i),
+      .dat1_i(ram_loader_dat_i),
+      .dat1_o(if_data),
+      .we1_i(ram_loader_done_i ? 1'b0 : ram_loader_we_i),
+      .en1_i(ram_loader_done_i ? 1'b1 : ram_loader_stb_i),
+      .sel1_i(ram_loader_done_i ? 4'hF : ram_loader_sel_i),
+      .adr2_i(dwb_adr_i),
+      .dat2_i(dwb_dat_i),
+      .dat2_o(dwb_dat_o),
+      .we2_i(dwb_we_i),
+      .en2_i(dwb_stb_i),
+      .sel2_i(dwb_sel_i) 
+      );
+
+   assign dwb_ack_o = dwb_stb_i & (dwb_we_i | (stb_d1 & ~ack_d1));
+
+   always @(posedge wb_clk_i) 
+     if(wb_rst_i)
+       ack_d1 <= 1'b0;
+     else 
+       ack_d1 <= dwb_ack_o;
+
+   always @(posedge wb_clk_i)
+     if(wb_rst_i)
+       stb_d1 <= 0;
+     else
+       stb_d1 <= dwb_stb_i;
+   
+
+endmodule // ram_harv_cache
diff --git a/usrp2/opencores/aemb/rtl/verilog/aeMB_bpcu.v b/usrp2/opencores/aemb/rtl/verilog/aeMB_bpcu.v
index a7c686e7e..81587e25c 100644
--- a/usrp2/opencores/aemb/rtl/verilog/aeMB_bpcu.v
+++ b/usrp2/opencores/aemb/rtl/verilog/aeMB_bpcu.v
@@ -125,7 +125,7 @@ module aeMB_bpcu (/*AUTOARG*/
    reg [31:2] 	   rPC, xPC;
    reg [31:2] 	   rPCLNK, xPCLNK;
    
-   assign 	   iwb_adr_o = rIPC[IW-1:2];
+   assign 	   iwb_adr_o = gena ? xIPC[IW-1:2] :  rIPC[IW-1:2]; //IJB
    
    always @(/*AUTOSENSE*/rBRA or rIPC or rPC or rRESULT) begin
       //xPCLNK <= (^rATOM) ? rPC : rPC;
@@ -168,7 +168,8 @@ module aeMB_bpcu (/*AUTOARG*/
 	rATOM <= 2'h0;
 	rBRA <= 1'h0;
 	rDLY <= 1'h0;
-	rIPC <= 30'h0;
+//	rIPC <= 30'h0;
+	rIPC <= 30'h3fffffff; // DWORD aligned address 
 	rPC <= 30'h0;
 	rPCLNK <= 30'h0;
 	// End of automatics
diff --git a/usrp2/opencores/aemb/rtl/verilog/aeMB_core_BE.v b/usrp2/opencores/aemb/rtl/verilog/aeMB_core_BE.v
index 9ffa20ff2..38ca3a023 100644
--- a/usrp2/opencores/aemb/rtl/verilog/aeMB_core_BE.v
+++ b/usrp2/opencores/aemb/rtl/verilog/aeMB_core_BE.v
@@ -10,12 +10,10 @@ module aeMB_core_BE
     parameter MUL=0, parameter BSF=0)
     (input sys_clk_i,
      input sys_rst_i,
-
-     output iwb_stb_o,
-     output [ISIZ-1:0] iwb_adr_o,
-     input [31:0] iwb_dat_i,
-     input iwb_ack_i,
-
+     // Instruction port
+     output [14:0] if_adr,
+     input [31:0] if_dat,
+     // Data port
      output dwb_we_o,
      output dwb_stb_o,
      output [DSIZ-1:0] dwb_adr_o,
@@ -28,17 +26,28 @@ module aeMB_core_BE
      input sys_int_i, 
      input sys_exc_i);
 
-   assign  dwb_cyc_o = dwb_stb_o;
 
+   wire [ISIZ-1:0] iwb_adr_o;
+   wire [31:0] 	   iwb_dat_i;
+   wire 	   iwb_ack_i;
+   wire 	   iwb_stb_o;
+   
+   assign dwb_cyc_o = dwb_stb_o;
+   assign iwb_ack_i = 1'b1;
+   assign if_adr = iwb_adr_o[14:0];
+   assign iwb_dat_i = if_dat;
+
+   // Note some "wishbone" instruction fetch signals pruned on external interface
+   // but not propogated change deep into aeMB.
    aeMB_edk32 #(.IW(ISIZ),.DW(DSIZ),.MUL(MUL),.BSF(BSF))
      aeMB_edk32 (.sys_clk_i(sys_clk_i), 
 		 .sys_rst_i(sys_rst_i),
-		 
+		 // Instruction Port
 		 .iwb_stb_o(iwb_stb_o),
 		 .iwb_adr_o(iwb_adr_o[ISIZ-1:2]),
 		 .iwb_ack_i(iwb_ack_i),
 		 .iwb_dat_i(iwb_dat_i),
-		 
+		 // Data port
 		 .dwb_wre_o(dwb_we_o),
 		 .dwb_stb_o(dwb_stb_o),
 		 .dwb_adr_o(dwb_adr_o[DSIZ-1:2]),
diff --git a/usrp2/top/u2_core/u2_core.v b/usrp2/top/u2_core/u2_core.v
index df74c7dba..5e0b569cc 100755
--- a/usrp2/top/u2_core/u2_core.v
+++ b/usrp2/top/u2_core/u2_core.v
@@ -284,8 +284,8 @@ module u2_core
    aeMB_core_BE #(.ISIZ(16),.DSIZ(16),.MUL(0),.BSF(1))
      aeMB (.sys_clk_i(wb_clk), .sys_rst_i(wb_rst),
 	   // Instruction Wishbone bus to I-RAM
-	   .iwb_stb_o(iwb_stb),.iwb_adr_o(iwb_adr),
-	   .iwb_dat_i(iwb_dat),.iwb_ack_i(iwb_ack),
+	   .if_adr(if_adr),
+	   .if_dat(if_dat),
 	   // Data Wishbone bus to system bus fabric
 	   .dwb_we_o(m0_we),.dwb_stb_o(m0_stb),.dwb_dat_o(m0_dat_i),.dwb_adr_o(m0_adr),
 	   .dwb_dat_i(m0_dat_o),.dwb_ack_i(m0_ack),.dwb_sel_o(m0_sel),.dwb_cyc_o(m0_cyc),
@@ -299,7 +299,7 @@ module u2_core
    // I-port connects directly to processor and ram loader
 
    wire 	 flush_icache;
-   ram_harv_cache #(.AWIDTH(15),.RAM_SIZE(RAM_SIZE),.ICWIDTH(7),.DCWIDTH(6))
+   ram_harvard #(.AWIDTH(15),.RAM_SIZE(RAM_SIZE),.ICWIDTH(7),.DCWIDTH(6))
      sys_ram(.wb_clk_i(wb_clk),.wb_rst_i(wb_rst),
 	     
 	     .ram_loader_adr_i(ram_loader_adr[14:0]), .ram_loader_dat_i(ram_loader_dat),
@@ -307,8 +307,8 @@ module u2_core
 	     .ram_loader_we_i(ram_loader_we), .ram_loader_ack_o(ram_loader_ack),
 	     .ram_loader_done_i(ram_loader_done),
 	     
-	     .iwb_adr_i(iwb_adr[14:0]), .iwb_stb_i(iwb_stb),
-	     .iwb_dat_o(iwb_dat), .iwb_ack_o(iwb_ack),
+	     .if_adr(if_adr), 
+	     .if_data(if_dat), 
 	     
 	     .dwb_adr_i(s0_adr[14:0]), .dwb_dat_i(s0_dat_o), .dwb_dat_o(s0_dat_i),
 	     .dwb_we_i(s0_we), .dwb_ack_o(s0_ack), .dwb_stb_i(s0_stb), .dwb_sel_i(s0_sel),
diff --git a/usrp2/top/u2_rev3/Makefile b/usrp2/top/u2_rev3/Makefile
index 80d09acb7..bfebcac8b 100644
--- a/usrp2/top/u2_rev3/Makefile
+++ b/usrp2/top/u2_rev3/Makefile
@@ -66,6 +66,7 @@ control_lib/mux4.v \
 control_lib/mux8.v \
 control_lib/nsgpio.v \
 control_lib/ram_2port.v \
+control_lib/ram_harvard.v \
 control_lib/ram_harv_cache.v \
 control_lib/ram_loader.v \
 control_lib/setting_reg.v \