From f0ded923cc20dbc39336f3f2e8f083033dba6f9c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joachim=20Stro=CC=88mbergson?= <joachim@secworks.se>
Date: Tue, 3 Feb 2015 21:45:24 +0100
Subject: (1) Updated core selector with logic to connect sha256. (2) Adding
 test sw that is able to talk to the sha256 core and perform a hash operation.

---
 rtl/src/verilog/core_selector.v | 106 ++++++++++++++++++++++++++++++++++------
 1 file changed, 90 insertions(+), 16 deletions(-)

(limited to 'rtl/src/verilog')

diff --git a/rtl/src/verilog/core_selector.v b/rtl/src/verilog/core_selector.v
index a18bfe6..3f74a26 100644
--- a/rtl/src/verilog/core_selector.v
+++ b/rtl/src/verilog/core_selector.v
@@ -48,26 +48,100 @@ module core_selector
 	 input wire [31 : 0]  write_data
 	);
 
-  localparam SHA256_BASE_ADDR = 6'h14;
-  wire access_sha256 = (sys_eim_addr[13 : 8] == SHA256_BASE_ADDR) ? 1'b1 : 1'b0;
-  wire read_access   = sys_eim_rd & access_sha256;
-  wire write_access  = sys_eim_wr & access_sha256;
-  wire select = read_access | write_access;
 
-  assign read_data = (sys_eim_rd) ? 32'hdeadbeef : 32'haa55aa55;
+  //
+  // Parameters
+  //
+  localparam	ADDER_BASE_ADDR		= 6'h00;	// upper 6 bits of address
+  localparam	ADDER_OFFSET_X_REG	= 8'h00;	// X
+  localparam	ADDER_OFFSET_Y_REG	= 8'h01;	// Y
 
-//  sha256 sha256_inst(
-//                     .clk(sys_clk),
-//                     .reset_n(~sys_rst),
+
+  /* This flag detects whether adder core is being addressed. */
+  wire eim_access_adder	= (sys_eim_addr[13:8] == ADDER_BASE_ADDR) ? 1'b1 : 1'b0;
+
+  /* These flags detect whether write or read access is requested. */
+  wire eim_access_write	= sys_eim_wr & eim_access_adder;
+  wire eim_access_read	= sys_eim_rd & eim_access_adder;
+  wire select = eim_access_read | eim_access_write;
+
+//  reg [31 : 0] read_data_reg;
+//  reg [31 : 0] y_reg;
+//  reg [31 : 0] x_reg;
+//
+//  //
+//  // Write Request Handler
+//  //
+//  always @(posedge sys_clk)
+//    //
+//    if (sys_rst) begin
+//      x_reg <= 32'hdeaddead;
+//      y_reg <= 32'hbeefbeef;
+//  end
+//    else if (eim_access_write) begin
+//      case (sys_eim_addr[7:0])
+//        ADDER_OFFSET_X_REG:  x_reg <= write_data;
+//        ADDER_OFFSET_Y_REG:  y_reg <= write_data;
+//      endcase
+//    end
+//
+//
+//  //
+//  // Read Request Handler
+//  always @(posedge sys_clk)
+//    //
+//    if (sys_rst)
+//      read_data_reg <= 32'h00000000;
+//    //
+//    else if (eim_access_read) begin
+//      //
+//      case (sys_eim_addr[7:0])
+//	ADDER_OFFSET_X_REG:	read_data_reg	<= x_reg;
+//	ADDER_OFFSET_Y_REG:	read_data_reg	<= y_reg;
+//      endcase
+//      //
+//    end
+
+//    assign read_data = read_data_reg;
+
+
+    //  localparam SHA256_BASE_ADDR = 6'h14;
+    //
+    //  wire access_sha256 = (sys_eim_addr[13 : 8] == SHA256_BASE_ADDR) ? 1'b1 : 1'b0;
+    //  wire read_access   = sys_eim_rd & access_sha256;
+    //  wire write_access  = sys_eim_wr & access_sha256;
+    //  wire select        = read_access | write_access;
+
+//  reg [31 : 0] read_data_reg;
+//  wire  [31 : 0] sha_read_data;
 //
-//                     .cs(select),
-//                     .we(write_access),
+//  assign read_data = read_data_reg;
 //
-//                     .address(sys_eim_addr[7 : 0]),
-//                     .write_data(write_data),
-//                     .read_data(read_data),
-//                     .error()
-//                    );
+//  always @ (posedge sys_clk)
+//    begin
+//      if (sys_rst)
+//        begin
+//          read_data_reg <= 32'h00000000;
+//        end
+//      else
+//        begin
+//          read_data_reg <= sha_read_data;
+//        end
+//    end
+
+
+  sha256 sha256_inst(
+                     .clk(sys_clk),
+                     .reset_n(1'b1),
+
+                     .cs(eim_access_adder),
+                     .we(sys_eim_wr),
+
+                     .address(sys_eim_addr[7 : 0]),
+                     .write_data(write_data),
+                     .read_data(read_data),
+                     .error()
+                    );
 
 endmodule
 
-- 
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