From 3e5a998a2cb380d90615b524b5e41c671ab8004d Mon Sep 17 00:00:00 2001
From: Julian Blake Kongslie
Date: Sun, 29 May 2022 16:38:00 -0700
Subject: Add support for bulk memory dumping to command parser.

---
 hdl/command_parser.sv | 67 ++++++++++++++++++++++++++++++++++-----------------
 1 file changed, 45 insertions(+), 22 deletions(-)

(limited to 'hdl/command_parser.sv')

diff --git a/hdl/command_parser.sv b/hdl/command_parser.sv
index 964ac12..1520db4 100644
--- a/hdl/command_parser.sv
+++ b/hdl/command_parser.sv
@@ -16,19 +16,23 @@ module command_parser
     ,   input   bit             command_ready
     ,   output  bit             command_valid
     ,   output  ram_command_t   command_data
+
+    ,   input   bit loop_ready
+    ,   output  bit loop_valid
+    ,   output  bit loop_data
     );
 
     bit         input_byte_valid;
     uart_byte_t input_byte;
 
-    bit [`RAM_ADDRESS_BITS:0]   zero_count;
+    bit [`RAM_ADDRESS_BITS:0]   loop_count;
 
     (* syn_encoding = "one-hot" *) enum int unsigned
         {   READ_COMMAND
         ,   READ_ADDRESS
         ,   READ_DATA
-        ,   READ_ZERO_COUNT
-        ,   ZERO_MEMORY
+        ,   READ_LOOP_COUNT
+        ,   LOOP_MEMORY
         } state;
 
     always @(posedge clock) begin
@@ -38,9 +42,10 @@ module command_parser
             for (int i = 0; i < `RAM_LINE_WORDS; i = i + 1)
                 command_data.mask[i] = ~0;
             command_data.tag = TAG;
+            loop_valid = 0;
             input_byte_valid = 0;
             input_byte = 0;
-            zero_count = 0;
+            loop_count = 0;
             state = state.first;
         end else begin
             if (echo_ready) echo_valid = 0;
@@ -54,8 +59,11 @@ module command_parser
                 input_byte_valid = 1;
                 input_byte = uart_data;
             end
+            if (loop_ready && loop_valid) begin
+                loop_valid = 0;
+            end
 
-            if (!command_valid) begin
+            if (!command_valid && !loop_valid) begin
                 case (state)
 
                 READ_COMMAND: if (input_byte_valid) begin
@@ -63,18 +71,24 @@ module command_parser
 
                     "@": begin
                         command_data.address = 0;
+                        loop_valid = 1;
+                        loop_data = 0;
                         state = READ_ADDRESS;
                     end
 
                     "?": begin
                         command_valid = 1;
                         command_data.write = 0;
+                        loop_valid = 1;
+                        loop_data = 0;
                     end
 
                     "=": begin
                         command_data.write = 1;
                         for (int i = 0; i < `RAM_LINE_WORDS; i = i + 1)
                             command_data.data[i] = 0;
+                        loop_valid = 1;
+                        loop_data = 0;
                         state = READ_DATA;
                     end
 
@@ -82,8 +96,14 @@ module command_parser
                         command_data.write = 1;
                         for (int i = 0; i < `RAM_LINE_WORDS; i = i + 1)
                             command_data.data[i] = 0;
-                        zero_count = 0;
-                        state = READ_ZERO_COUNT;
+                        loop_count = 0;
+                        state = READ_LOOP_COUNT;
+                    end
+
+                    "#": begin
+                        command_data.write = 0;
+                        loop_count = 0;
+                        state = READ_LOOP_COUNT;
                     end
 
                     endcase
@@ -129,27 +149,29 @@ module command_parser
                     input_byte_valid = 0;
                 end
 
-                READ_ZERO_COUNT: if (input_byte_valid) begin
+                READ_LOOP_COUNT: if (input_byte_valid) begin
                     if (input_byte == ":") begin
                         // ignore
                     end else if (input_byte >= "0" && input_byte <= "9") begin
-                        zero_count = zero_count << 4;
-                        zero_count[3:0] = input_byte - "0";
+                        loop_count = loop_count << 4;
+                        loop_count[3:0] = input_byte - "0";
                     end else if (input_byte >= "a" && input_byte <= "f") begin
-                        zero_count = zero_count << 4;
-                        zero_count[3:0] = input_byte - "a" + 10;
+                        loop_count = loop_count << 4;
+                        loop_count[3:0] = input_byte - "a" + 10;
                     end else if (input_byte >= "A" && input_byte <= "F") begin
-                        zero_count = zero_count << 4;
-                        zero_count[3:0] = input_byte - "A" + 10;
+                        loop_count = loop_count << 4;
+                        loop_count[3:0] = input_byte - "A" + 10;
                     end else begin
-                        state = ZERO_MEMORY;
+                        loop_valid = 1;
+                        loop_data = 1;
+                        state = LOOP_MEMORY;
                     end
                     input_byte_valid = 0;
                 end
 
-`ifdef SLOW_ZEROING
-                ZERO_MEMORY: if (!echo_valid) begin
-                    if (zero_count == 0) begin
+`ifdef SLOW_LOOPING
+                LOOP_MEMORY: if (!echo_valid) begin
+                    if (loop_count == 0) begin
                         echo_valid = 1;
                         echo_data = "\n";
                         state = state.first;
@@ -157,17 +179,18 @@ module command_parser
                         echo_valid = 1;
                         echo_data = ".";
                         command_valid = 1;
-                        --zero_count;
+                        --loop_count;
                     end
                 end
 `else
-                ZERO_MEMORY: begin
-                    if (zero_count == 0) begin
+                LOOP_MEMORY: begin
+                    if (loop_count == 0) begin
                         state = state.first;
                     end else begin
                         command_valid = 1;
-                        if (--zero_count == 0)
+                        if (--loop_count == 0) begin
                             state = state.first;
+                        end
                     end
                 end
 `endif
-- 
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