common: reset cleanup for gc_frequency_meter

67d353ad · Dimitris Lampridis · 66e128d0 · 67d353ad · 67d353ad
Commit 67d353ad authored May 20, 2019 by Dimitris Lampridis
Hide whitespace changes
Inline Side-by-side

Showing with 19 additions and 29 deletions

gc_frequency_meter.vhd modules/common/gc_frequency_meter.vhd +12 -20

gc_pulse_synchronizer2.vhd modules/common/gc_pulse_synchronizer2.vhd +7 -9

No files found.
--- a/modules/common/gc_frequency_meter.vhd
+++ b/modules/common/gc_frequency_meter.vhd
@@ -39,7 +39,7 @@ entity gc_frequency_meter is
  port(
    clk_sys_i    : in  std_logic;
    clk_in_i     : in  std_logic;
-    rst_n_i      : in  std_logic;
+    rst_n_i      : in  std_logic; -- not used, kept for backward compatibility
    pps_p1_i     : in  std_logic;
    freq_o       : out std_logic_vector(g_counter_bits-1 downto 0);
    freq_valid_o : out std_logic
@@ -50,11 +50,11 @@ end gc_frequency_meter;

 architecture behavioral of gc_frequency_meter is

-  signal gate_pulse, gate_pulse_synced : std_logic;
+  signal gate_pulse, gate_pulse_synced : std_logic := '0';

-  signal cntr_gate : unsigned(g_counter_bits-1 downto 0);
-  signal cntr_meas : unsigned(g_counter_bits-1 downto 0);
-  signal freq_reg  : std_logic_vector(g_counter_bits-1 downto 0);
+  signal cntr_gate : unsigned(g_counter_bits-1 downto 0) := (others => '0');
+  signal cntr_meas : unsigned(g_counter_bits-1 downto 0) := (others => '0');
+  signal freq_reg  : std_logic_vector(g_counter_bits-1 downto 0) := (others => '0');

 begin

@@ -63,17 +63,12 @@ begin
    p_gate_counter : process(clk_sys_i)
    begin
      if rising_edge(clk_sys_i) then
-        if rst_n_i = '0' then
+        if(cntr_gate = g_clk_sys_freq-1) then
          cntr_gate  <= (others => '0');
-          gate_pulse <= '0';
+          gate_pulse <= '1';
        else
-          if(cntr_gate = g_clk_sys_freq-1) then
-            cntr_gate  <= (others => '0');
-            gate_pulse <= '1';
-          else
-            cntr_gate  <= cntr_gate + 1;
-            gate_pulse <= '0';
-          end if;
+          cntr_gate  <= cntr_gate + 1;
+          gate_pulse <= '0';
        end if;
      end if;
    end process;
@@ -82,7 +77,7 @@ begin
    port map (
      clk_in_i  => clk_sys_i,
      clk_out_i => clk_in_i,
-      rst_n_i   => rst_n_i,
+      rst_n_i   => '1',
      d_ready_o => freq_valid_o,
      d_p_i     => gate_pulse,
      q_p_o     => gate_pulse_synced);
@@ -95,7 +90,7 @@ begin
    port map (
      clk_in_i  => clk_sys_i,
      clk_out_i => clk_in_i,
-      rst_n_i   => rst_n_i,
+      rst_n_i   => '1',
      d_ready_o => freq_valid_o,
      d_p_i     => pps_p1_i,
      q_p_o     => gate_pulse_synced);
@@ -105,10 +100,7 @@ begin

  p_freq_counter : process (clk_in_i, rst_n_i)
  begin
-    if rst_n_i = '0' then               -- asynchronous reset (active low)
-      cntr_meas <= (others => '0');
-      freq_reg  <= (others => '0');
-    elsif rising_edge(clk_in_i) then
+    if rising_edge(clk_in_i) then
      
      if(gate_pulse_synced = '1') then
        freq_reg  <= std_logic_vector(cntr_meas);

--- a/modules/common/gc_pulse_synchronizer2.vhd
+++ b/modules/common/gc_pulse_synchronizer2.vhd
@@ -49,9 +49,11 @@ end gc_pulse_synchronizer2;

 architecture rtl of gc_pulse_synchronizer2 is

-  signal ready, d_p_d0   : std_logic;
-  signal in_ext, out_ext : std_logic;
-  signal out_feedback    : std_logic;
+  signal ready        : std_logic := '1';
+  signal d_p_d0       : std_logic := '0';
+  signal in_ext       : std_logic := '0';
+  signal out_ext      : std_logic := '0';
+  signal out_feedback : std_logic := '0';

 begin  -- rtl

@@ -73,13 +75,9 @@ begin  -- rtl
      npulse_o => open,
      ppulse_o => open);

-  p_input_ack : process(clk_in_i, rst_in_n_i)
+  p_input_ack : process(clk_in_i)
  begin
-    if rst_in_n_i = '0' then
-      ready  <= '1';
-      in_ext <= '0';
-      d_p_d0 <= '0';
-    elsif rising_edge(clk_in_i) then
+    if rising_edge(clk_in_i) then

      d_p_d0 <= d_p_i;