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1 -- J.STELZNER
2 -- INFORMATIK-3 LABOR
3 -- 23.08.2006
4 -- File: CONFIG_WR_SEL.VHD
5
6 library IEEE;
7 use IEEE.std_logic_1164.all;
8
9 entity IO_WR_SEL is
10 port
11 (
12 IO_WR_COM :in std_logic;
13 IRDY_REGn :in std_logic;
14 TRDYn :in std_logic;
15 ADDR_REG :in std_logic_vector(31 downto 0);
16 CBE_REGn :in std_logic_vector( 3 downto 0);
17 WRITE_XX1_0 :out std_logic;
18 WRITE_XX3_2 :out std_logic;
19 WRITE_XX5_4 :out std_logic;
20 WRITE_XX7_6 :out std_logic
21 );
22 end entity IO_WR_SEL;
23
24 --PCI Byte Enable
25 --C/BE[3..0] gueltige Datenbits
26 -------------------------------
27 -- 0000 AD 31..0
28 -- 1000 AD 23..0
29 -- 1100 AD 15..0
30 -- 1110 AD 7..0
31 -- 0011 AD 31..16
32
33 architecture IO_WR_SEL_DESIGN of IO_WR_SEL is
34
35 signal WR_ENA :std_logic;
36 signal ADDR :std_logic_vector( 5 downto 0);
37
38 begin
39
40 WR_ENA <= '1' when
41 IO_WR_COM = '1' and
42 IRDY_REGn = '0' and
43 TRDYn = '0' else '0';
44
45 ADDR <= ADDR_REG(3) & ADDR_REG(2) & CBE_REGn;
46
47 WRITE_XX1_0 <= '1' when WR_ENA = '1' and ADDR = "001100" else '0';
48 WRITE_XX3_2 <= '1' when WR_ENA = '1' and ADDR = "000011" else '0';
49 WRITE_XX5_4 <= '1' when WR_ENA = '1' and ADDR = "011100" else '0';
50 WRITE_XX7_6 <= '1' when WR_ENA = '1' and ADDR = "010011" else '0';
51
52 end architecture IO_WR_SEL_DESIGN;
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