From 1304440b303fd4d9b135f364e4b9ce0dd923097e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Joachim=20Stro=CC=88mbergson?= <joachim@secworks.se>
Date: Fri, 7 Dec 2018 10:47:54 +0100
Subject: Adding API support for key loaded status and key timeout control.
 Added ports in the core to support key status and timeout. Updated core
 testbench to match the new interface.

---
 src/rtl/keywrap.v        | 33 +++++++++++++++++++++++++++++----
 src/rtl/keywrap_core.v   |  3 +++
 src/tb/tb_keywrap_core.v |  5 +++++
 3 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/src/rtl/keywrap.v b/src/rtl/keywrap.v
index f8fcbd7..023ed14 100644
--- a/src/rtl/keywrap.v
+++ b/src/rtl/keywrap.v
@@ -73,14 +73,17 @@ module keywrap #(parameter ADDR_BITS = 13)
   localparam CTRL_INIT_BIT    = 0;
   localparam CTRL_NEXT_BIT    = 1;
 
-  localparam ADDR_STATUS      = 8'h09;
-  localparam STATUS_READY_BIT = 0;
-  localparam STATUS_VALID_BIT = 1;
+  localparam ADDR_STATUS       = 8'h09;
+  localparam STATUS_READY_BIT  = 0;
+  localparam STATUS_VALID_BIT  = 1;
+  localparam STATUS_LOADED_BIT = 2;
 
   localparam ADDR_CONFIG      = 8'h0a;
   localparam CTRL_ENCDEC_BIT  = 0;
   localparam CTRL_KEYLEN_BIT  = 1;
 
+  localparam ADDR_TIMEOUT     = 8'h0b;
+
   localparam ADDR_RLEN        = 8'h0c;
   localparam ADDR_A0          = 8'h0e;
   localparam ADDR_A1          = 8'h0f;
@@ -102,6 +105,8 @@ module keywrap #(parameter ADDR_BITS = 13)
   localparam RLEN_BITS        = ADDR_BITS - 2;
   localparam PAD              = ADDR_BITS - 8;
 
+  localparam DEFAULT_TIMEOUT  = 32'hffff0000;
+
 
   //----------------------------------------------------------------
   // Registers including update variables and write enable.
@@ -128,11 +133,15 @@ module keywrap #(parameter ADDR_BITS = 13)
   reg [31 : 0] key_reg [0 : 7];
   reg          key_we;
 
+  reg [31 : 0] timeout_reg;
+  reg          timeout_we;
+
   reg [31 : 0] api_rd_delay_reg;
   reg [31 : 0] api_rd_delay_new;
 
   reg valid_reg;
   reg ready_reg;
+  reg loaded_reg;
 
 
   //----------------------------------------------------------------
@@ -145,6 +154,7 @@ module keywrap #(parameter ADDR_BITS = 13)
   wire [(MEM_BITS - 1) : 0] core_api_addr;
   wire           core_ready;
   wire           core_valid;
+  wire           core_loaded;
   wire [255 : 0] core_key;
   wire [63 : 0]  core_a_init;
   wire [63 : 0]  core_a_result;
@@ -179,6 +189,9 @@ module keywrap #(parameter ADDR_BITS = 13)
 
                     .ready(core_ready),
                     .valid(core_valid),
+                    .loaded(core_loaded),
+
+                    .timeout(timeout_reg),
 
                     .rlen(rlen_reg),
 
@@ -214,14 +227,17 @@ module keywrap #(parameter ADDR_BITS = 13)
           rlen_reg         <= {RLEN_BITS{1'h0}};
           valid_reg        <= 1'h0;
           ready_reg        <= 1'h0;
+          loaded_reg       <= 1'h0;
           a0_reg           <= 32'h0;
           a1_reg           <= 32'h0;
           api_rd_delay_reg <= 32'h0;
+          timeout_reg      <= DEFAULT_TIMEOUT;
         end
       else
         begin
           ready_reg        <= core_ready;
           valid_reg        <= core_valid;
+          loaded_reg       <= core_loaded;
           init_reg         <= init_new;
           next_reg         <= next_new;
           api_rd_delay_reg <= api_rd_delay_new;
@@ -243,6 +259,9 @@ module keywrap #(parameter ADDR_BITS = 13)
 
           if (key_we)
             key_reg[address[2 : 0]] <= write_data;
+
+          if (timeout_we)
+            timeout_reg <= write_data;
         end
     end // reg_update
 
@@ -285,6 +304,9 @@ module keywrap #(parameter ADDR_BITS = 13)
               if (address == {{PAD{1'h0}}, ADDR_CONFIG})
                 config_we = 1'h1;
 
+              if (address == {{PAD{1'h0}}, ADDR_TIMEOUT})
+                timeout_we = 1'h1;
+
               if (address == {{PAD{1'h0}}, ADDR_RLEN})
                 rlen_we = 1'h1;
 
@@ -317,7 +339,10 @@ module keywrap #(parameter ADDR_BITS = 13)
                 api_rd_delay_new = {28'h0, keylen_reg, encdec_reg, next_reg, init_reg};
 
               if (address == {{PAD{1'h0}}, ADDR_STATUS})
-                api_rd_delay_new = {30'h0, valid_reg, ready_reg};
+                api_rd_delay_new = {29'h0, loaded_reg, valid_reg, ready_reg};
+
+              if (address == {{PAD{1'h0}}, ADDR_TIMEOUT})
+                api_rd_delay_new = timeout_reg;
 
               if (address == {{PAD{1'h0}}, ADDR_RLEN})
                 api_rd_delay_new = {19'h0, rlen_reg};
diff --git a/src/rtl/keywrap_core.v b/src/rtl/keywrap_core.v
index d1e63b0..b16e05d 100644
--- a/src/rtl/keywrap_core.v
+++ b/src/rtl/keywrap_core.v
@@ -51,6 +51,9 @@ module keywrap_core #(parameter MEM_BITS = 11)
 
                      output wire                      ready,
                      output wire                      valid,
+                     output wire                      loaded,
+
+                     input wire [31 : 0]              timeout,
 
                      input wire [(MEM_BITS - 2) : 0]  rlen,
 
diff --git a/src/tb/tb_keywrap_core.v b/src/tb/tb_keywrap_core.v
index 17c8f30..1212ad7 100644
--- a/src/tb/tb_keywrap_core.v
+++ b/src/tb/tb_keywrap_core.v
@@ -67,6 +67,8 @@ module tb_keywrap_core();
   reg                           tb_encdec;
   wire                          tb_ready;
   wire                          tb_valid;
+  wire                          tb_loaded;
+  reg [31 : 0]                  tb_timeout;
   reg [(RLEN_BITS - 1) : 0]     tb_rlen;
   reg [255 : 0]                 tb_key;
   reg                           tb_keylen;
@@ -92,6 +94,9 @@ module tb_keywrap_core();
 
                    .ready(tb_ready),
                    .valid(tb_valid),
+                   .loaded(tb_loaded),
+
+                   .timeout(tb_timeout),
 
                    .rlen(tb_rlen),
                    .key(tb_key),
-- 
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