From 0553c4839c06011bd044f69b4913e5c793fdd2ec Mon Sep 17 00:00:00 2001
From: Julian Blake Kongslie
Date: Sun, 27 Feb 2022 17:21:05 -0800
Subject: Initial commit.

---
 hdl/result_printer.sv | 71 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)
 create mode 100644 hdl/result_printer.sv

(limited to 'hdl/result_printer.sv')

diff --git a/hdl/result_printer.sv b/hdl/result_printer.sv
new file mode 100644
index 0000000..3041e6e
--- /dev/null
+++ b/hdl/result_printer.sv
@@ -0,0 +1,71 @@
+`include "defs.svh"
+
+module result_printer
+    #(  TAG = 0
+    ) ( input   bit                 clock
+    ,   input   bit                 reset
+
+    ,   output  bit                 result_ready
+    ,   input   bit                 result_valid
+    ,   input   ram_read_response_t result_data
+
+    ,   input   bit         echo_ready
+    ,   output  bit         echo_valid
+    ,   output  uart_byte_t echo_data
+    );
+
+    ram_read_response_t hold;
+    ram_byte_count_t    byte_count;
+    ram_word_count_t    word_count;
+
+    (* syn_encoding = "one-hot" *) enum int unsigned
+        {   HIGH_NIBBLE
+        ,   LOW_NIBBLE
+        } state;
+
+    always @(posedge clock) begin
+        if (reset) begin
+            result_ready = 0;
+            echo_valid = 0;
+            echo_data = 0;
+            byte_count = 0;
+            word_count = 0;
+            state = state.first;
+        end else begin
+            if (echo_ready) echo_valid = 0;
+            if (result_ready && result_valid) begin
+                hold = result_data;
+                if (hold.tag == TAG) begin
+                    byte_count = `RAM_WORD_BYTES;
+                    word_count = `RAM_LINE_WORDS;
+                    state = state.first;
+                end
+            end
+
+            if (word_count != 0 && !echo_valid) begin
+                automatic ram_word_t w = hold.data[word_count-1];
+                automatic ram_byte_t b = w[byte_count-1];
+                echo_valid = 1;
+                case (state)
+                HIGH_NIBBLE: echo_data = b[7:4];
+                LOW_NIBBLE: echo_data = b[3:0];
+                endcase
+                if (echo_data < 10)
+                    echo_data = echo_data + "0";
+                else
+                    echo_data = echo_data + "A" - 10;
+                state = state.next;
+                if (state == state.first) begin
+                    byte_count = byte_count - 1;
+                    if (byte_count == 0) begin
+                        byte_count = `RAM_WORD_BYTES;
+                        word_count = word_count - 1;
+                    end
+                end
+            end
+
+            result_ready = word_count == 0;
+        end
+    end
+
+endmodule
-- 
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