Omsp_quadcount periphery changed.

[fpga/virtex2/uart.git] / omsp_quadcount.vhd

diff --git a/omsp_quadcount.vhd b/omsp_quadcount.vhd
index 43e9750793fc26e621d1c5f02c822f36c860375e..c58c5ed64bb7f476474e21b8da05afa623a5d7f4 100644 (file)
--- a/omsp_quadcount.vhd
+++ b/omsp_quadcount.vhd
@@ -7,18 +7,18 @@ entity omsp_quadcount is
   generic (
     ADDR : std_logic_vector (15 downto 0) := X"0150");
   port (
-    mclk        : in  std_logic;
-    per_addr    : in  std_logic_vector (7  downto 0);
-    per_din     : in  std_logic_vector (15 downto 0);  -- unused
-    per_en      : in  std_logic;
-    per_wen     : in  std_logic_vector (1  downto 0);  -- unused
-    puc         : in  std_logic;                       -- unused
-    per_irq_acc : in  std_logic;                       -- unused
-    per_irq     : out std_logic;
-    per_dout    : out std_logic_vector (15 downto 0);
-    
-    qcount      : in  std_logic_vector (31 downto 0)
-  );
+    -- MCU peripheral interface
+    mclk     : in  std_logic;
+    puc      : in  std_logic;
+    per_addr : in  std_logic_vector (7 downto 0);
+    per_en   : in  std_logic;
+    per_irq  : out std_logic;
+    per_dout : out std_logic_vector (15 downto 0);
+    -- QCounter component interface
+    qclk     : in  std_logic;
+    qreset   : in  std_logic;
+    a0, b0   : in  std_logic;
+    qcount   : out std_logic_vector (31 downto 0));
 end omsp_quadcount;
 
 --------------------------------------------------------------------------------
@@ -34,42 +34,86 @@ architecture behavioral of omsp_quadcount is
     -- qcount higher word logic address
   constant QCNTH : std_logic_vector (15 downto 0) := ADDR + 2;
 
+  -- Address read decoder
   signal qcntl_sel : boolean;
   signal qcnth_sel : boolean;
 
-  signal qcnth_latch : std_logic_vector (15 downto 0) := (others => '0');
-
-  signal qcount_prev : std_logic_vector (31 downto 0) := (others => '0');
-
+  -- Latch of high work of qcounter component
+  signal qcnth_latch : std_logic_vector (15 downto 0);
+
+  signal qcount_out : std_logic_vector (31 downto 0);
+  -- AB error of qcounter component (lead in peripheral irq)
+  signal ab_error : std_logic;
+  
+
+  component qcounter is
+    port (
+      clock    : in  std_logic;
+      reset    : in  std_logic;
+      a0, b0   : in  std_logic;
+      qcount   : out std_logic_vector (31 downto 0);
+      a_rise   : out std_logic;
+      a_fall   : out std_logic;
+      b_rise   : out std_logic;
+      b_fall   : out std_logic;
+      ab_event : out std_logic;
+      ab_error : out std_logic);
+  end component qcounter;
+  
 --------------------------------------------------------------------------------
 
 begin
 
+  qcounter_1: qcounter
+    port map (
+      clock    => qclk,
+      reset    => qreset,
+      a0       => a0,
+      b0       => b0,
+      qcount   => qcount_out,
+      a_rise   => open,
+      a_fall   => open,
+      b_rise   => open,
+      b_fall   => open,
+      ab_event => open,
+      ab_error => ab_error);
+
+  
   qcntl_sel <= (per_addr = QCNTL(8 downto 1)) and (per_en = '1');
   qcnth_sel <= (per_addr = QCNTH(8 downto 1)) and (per_en = '1');
 
-  per_dout <= qcount (15 downto 0) when qcntl_sel else
-              qcnth_latch          when qcnth_sel else
+  per_dout <= qcount_out (15 downto 0) when qcntl_sel else
+              qcnth_latch              when qcnth_sel else
               (others => '0');
 
-
-  process (mclk)
+  qcount <= qcount_out;
+  
+  
+  -- QCNTL latch.
+  process (mclk, puc)
   begin
-    if (rising_edge(mclk) and qcntl_sel) then
-      qcnth_latch <= qcount (31 downto 16);
+    if (puc = '1') then
+      qcnth_latch <= (others => '0');
+      
+    elsif (rising_edge(mclk) and qcntl_sel) then
+      qcnth_latch <= qcount_out (31 downto 16);
+      
     end if;
   end process;
 
-  -- Generation of IRQ signal. (changes in lower 2 bits are suppresed)
-  process (mclk)
+  -- Generation of IRQ signal. IRQ is cleared by QCNTL read operation.
+  process (mclk, puc)
   begin
-    if (rising_edge(mclk)) then
-      qcount_prev <= qcount;
-      
-      if (qcntl_sel) then
-        per_irq <= '0';
-      elsif (qcount_prev (31 downto 2) /= qcount (31 downto 2)) then
+    if (puc = '1') then
+      per_irq <= '0';
+
+    elsif (rising_edge(mclk)) then
+      if (ab_error = '1') then
         per_irq <= '1';
+        
+      elsif (qcntl_sel) then
+        per_irq <= '0';
+        
       end if;
     end if;
   end process;