X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/raggedstone/blobdiff_plain/0b6ed0d89260ade25dc0c2dc9fb8aa154fabd6a1..30273618403fd6512926c89f999f97b4722e1709:/dhwk/source/pci/fifo_io_control.vhd

diff --git a/dhwk/source/pci/fifo_io_control.vhd b/dhwk/source/pci/fifo_io_control.vhd
new file mode 100644
index 0000000..f9faba3
--- /dev/null
+++ b/dhwk/source/pci/fifo_io_control.vhd
@@ -0,0 +1,110 @@
+-- $Id: fifo_io_control.vhd,v 1.1 2007-03-11 08:55:29 sithglan Exp $
+
+library IEEE;
+use IEEE.std_logic_1164.all;
+
+entity FIFO_IO_CONTROL is
+        port
+        (
+                PCI_CLOCK :in std_logic;
+                WRITE_XX1_0 :in std_logic; -- PCI Write
+                FIFO_RDn :in std_logic; -- FIFO Read (low active)
+                RESET :in std_logic;
+                SYNC_FLAG_1 :in std_logic; -- Recv FIFO Empty (low active)
+                SYNC_FLAG_7 :in std_logic; -- Send FIFO Full (low active)
+                S_FIFO_RESETn :out std_logic; -- Send FIFO Reset (low active)
+                R_FIFO_RESETn :out std_logic; -- Recv FIFO Reset (low active)
+                S_FIFO_WRITEn :out std_logic; -- Send FIFO Write (low active)
+                R_FIFO_READn :out std_logic; -- Recv FIFO Read (low active)
+                S_FIFO_RETRANSMITn :out std_logic; -- Send FIFO Retransmit (low active)
+                R_FIFO_RETRANSMITn :out std_logic; -- Recv FIFO Retransmit (low active)
+                S_ERROR :out std_logic; -- Send ERROR
+                R_ERROR :out std_logic; -- Recv ERROR
+                SR_ERROR :out std_logic -- Send / Recv Error
+        );
+end entity FIFO_IO_CONTROL;
+
+architecture FIFO_IO_CONTROL_DESIGN of FIFO_IO_CONTROL is
+
+        signal SIG_S_ERROR :std_logic; -- Send Error
+        signal SIG_R_ERROR :std_logic; -- Recv Error
+
+begin
+
+ -- FIFO Write
+
+        process (PCI_CLOCK)
+        begin
+                if (PCI_CLOCK'event and PCI_CLOCK = '1') then
+                        if (RESET = '1') then
+                                S_FIFO_WRITEn <= '1';
+                                SIG_S_ERROR <= '0';
+
+                        elsif (WRITE_XX1_0 = '0') then
+                                S_FIFO_WRITEn <= '1';
+
+                        elsif (WRITE_XX1_0 = '1') then
+                                if (SYNC_FLAG_7 = '0') then
+                                        SIG_S_ERROR <= '1';
+
+                                elsif (SYNC_FLAG_7 = '1') then
+                                        S_FIFO_WRITEn <= '0';
+                                        SIG_S_ERROR <= '0';
+                                end if;
+                        end if;
+                end if;
+        end process;
+
+        S_ERROR <= SIG_S_ERROR;
+
+ -- FIFO Read
+
+        R_FIFO_READn <= FIFO_RDn;
+
+-- Receive Error
+
+        process (PCI_CLOCK)
+        begin
+                if (PCI_CLOCK'event and PCI_CLOCK ='1') then
+                        if (RESET = '1') then
+                                SIG_R_ERROR <= '0';
+
+                        elsif (FIFO_RDn = '0' and SYNC_FLAG_1 = '0') then
+                                SIG_R_ERROR <= '1';
+                        end if;
+                end if;
+        end process;
+
+        R_ERROR <= SIG_R_ERROR;
+
+-- Send or Receive Error
+
+        process (PCI_CLOCK)
+        begin
+                if (PCI_CLOCK'event and PCI_CLOCK ='1') then
+                        SR_ERROR <= SIG_S_ERROR or SIG_R_ERROR;
+                end if;
+        end process;
+
+-- FIFO Reset
+
+        process (PCI_CLOCK)
+        begin
+                if (PCI_CLOCK'event and PCI_CLOCK ='1') then
+                        S_FIFO_RESETn <= not RESET;
+                        R_FIFO_RESETn <= not RESET;
+                end if;
+        end process;
+
+
+-- FIFO Retransmit
+
+        process (PCI_CLOCK)
+        begin
+                if (PCI_CLOCK'event and PCI_CLOCK ='1') then
+                        S_FIFO_RETRANSMITn <= '1';
+                        R_FIFO_RETRANSMITn <= '1';
+                end if;
+        end process;
+
+end architecture FIFO_IO_CONTROL_DESIGN;