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

diff --git a/dhwk/source/pci/io_rw_sel.vhd b/dhwk/source/pci/io_rw_sel.vhd
new file mode 100644
index 0000000..dc8b913
--- /dev/null
+++ b/dhwk/source/pci/io_rw_sel.vhd
@@ -0,0 +1,52 @@
+-- J.STELZNER
+-- INFORMATIK-3 LABOR
+-- 23.08.2006
+-- File: CONFIG_WR_SEL.VHD
+
+library IEEE;
+use IEEE.std_logic_1164.all;
+
+entity IO_WR_SEL is
+        port
+        (
+                IO_WR_COM :in std_logic;
+                IRDY_REGn :in std_logic;
+                TRDYn :in std_logic;
+                ADDR_REG :in std_logic_vector(31 downto 0);
+                CBE_REGn :in std_logic_vector( 3 downto 0);
+                WRITE_XX1_0 :out std_logic;
+                WRITE_XX3_2 :out std_logic;
+                WRITE_XX5_4 :out std_logic;
+                WRITE_XX7_6 :out std_logic
+        );
+end entity IO_WR_SEL;
+
+--PCI Byte Enable
+--C/BE[3..0] gueltige Datenbits
+-------------------------------
+-- 0000 AD 31..0
+-- 1000 AD 23..0
+-- 1100 AD 15..0
+-- 1110 AD 7..0
+-- 0011 AD 31..16
+
+architecture IO_WR_SEL_DESIGN of IO_WR_SEL is
+
+        signal WR_ENA :std_logic;
+        signal ADDR :std_logic_vector( 5 downto 0);
+
+begin
+
+        WR_ENA <= '1' when
+                  IO_WR_COM = '1' and
+                  IRDY_REGn = '0' and
+                  TRDYn = '0' else '0';
+
+        ADDR <= ADDR_REG(3) & ADDR_REG(2) & CBE_REGn;
+
+        WRITE_XX1_0 <= '1' when WR_ENA = '1' and ADDR = "001100" else '0';
+        WRITE_XX3_2 <= '1' when WR_ENA = '1' and ADDR = "000011" else '0';
+        WRITE_XX5_4 <= '1' when WR_ENA = '1' and ADDR = "011100" else '0';
+        WRITE_XX7_6 <= '1' when WR_ENA = '1' and ADDR = "010011" else '0';
+
+end architecture IO_WR_SEL_DESIGN;