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| | 范例:opencore组织RISCMCU IP Core全套最新代码 _iodecoder |  | ---------------------------------------------------------------------------- ---- ----
 ---- WISHBONE RISCMCU IP Core ----
 ---- ----
 ---- This file is part of the RISCMCU project ----
 ---- http://www.opencores.org/projects/riscmcu/ ----
 ---- ----
 ---- Description ----
 ---- Implementation of a RISC Microcontroller based on Atmel AVR ----
 ---- AT90S1200 instruction set and features with Altera Flex10k20 FPGA. ----
 ---- ----
 ---- Author(s): ----
 ---- - Yap Zi He, yapzihe@hotmail.com ----
 ---- ----
 ----------------------------------------------------------------------------
 ---- ----
 ---- Copyright (C) 2001 Authors and OPENCORES.ORG ----
 ---- ----
 ---- This source file may be used and distributed without ----
 ---- restriction provided that this copyright statement is not ----
 ---- removed from the file and that any derivative work contains ----
 ---- the original copyright notice and the associated disclaimer. ----
 ---- ----
 ---- This source file is free software; you can redistribute it ----
 ---- and/or modify it under the terms of the GNU Lesser General ----
 ---- Public License as published by the Free Software Foundation; ----
 ---- either version 2.1 of the License, or (at your option) any ----
 ---- later version. ----
 ---- ----
 ---- This source is distributed in the hope that it will be ----
 ---- useful, but WITHOUT ANY WARRANTY; without even the implied ----
 ---- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ----
 ---- PURPOSE. See the GNU Lesser General Public License for more ----
 ---- details. ----
 ---- ----
 ---- You should have received a copy of the GNU Lesser General ----
 ---- Public License along with this source; if not, download it ----
 ---- from http://www.opencores.org/lgpl.shtml ----
 ---- ----
 ----------------------------------------------------------------------------
 library ieee;
 use ieee.std_logic_1164.all;
 entity v_iodecoder is
 port( ioaddr : in integer range 0 to 16#3f#;
 rd_io, wr_io : in std_logic;
 rd_sreg, wr_sreg : out std_logic;
 rd_gimsk, wr_gimsk, rd_timsk, wr_timsk, rd_tifr,wr_tifr : out std_logic;
 rd_mcucr,wr_mcucr, rd_tccr0, wr_tccr0, rd_tcnt0,wr_tcnt0 : out std_logic;
 rd_portb, wr_portb, rd_ddrb, wr_ddrb, rd_pinb : out std_logic;
 rd_portc, wr_portc, rd_ddrc, wr_ddrc, rd_pinc : out std_logic;
 rd_portd, wr_portd, rd_ddrd, wr_ddrd, rd_pind : out std_logic
 );
 end v_iodecoder;
 architecture iodecoder of v_iodecoder is
 begin
 process(rd_io, ioaddr)
 begin
 rd_sreg <= '0';
 rd_gimsk <= '0';
 rd_timsk <= '0';
 rd_tifr <= '0';
 rd_mcucr <= '0';
 rd_tccr0 <= '0';
 rd_tcnt0 <= '0';
 rd_portb <= '0';
 rd_ddrb <= '0';
 rd_pinb <= '0';
 rd_portc <= '0';
 rd_ddrc <= '0';
 rd_pinc <= '0';
 rd_portd <= '0';
 rd_ddrd <= '0';
 rd_pind <= '0';
 if rd_io = '1' then
 case ioaddr is
 when 16#3f# => rd_sreg <= '1';
 when 16#3b# => rd_gimsk <= '1';
 when 16#39# => rd_timsk <= '1';
 when 16#38# => rd_tifr <= '1';
 when 16#35# => rd_mcucr <= '1';
 when 16#33# => rd_tccr0 <= '1';
 when 16#32# => rd_tcnt0 <= '1';
 when 16#18# => rd_portb <= '1';
 when 16#17# => rd_ddrb <= '1';
 when 16#16# => rd_pinb <= '1';
 when 16#15# => rd_portc <= '1';
 when 16#14# => rd_ddrc <= '1';
 when 16#13# => rd_pinc <= '1';
 when 16#12# => rd_portd <= '1';
 when 16#11# => rd_ddrd <= '1';
 when 16#10# => rd_pind <= '1';
 when others =>
 end case;
 end if;
 end process;
 process(wr_io, ioaddr)
 begin
 wr_sreg <= '0';
 wr_gimsk <= '0';
 wr_timsk <= '0';
 wr_tifr <= '0';
 wr_mcucr <= '0';
 wr_tccr0 <= '0';
 wr_tcnt0 <= '0';
 
 wr_portb <= '0';
 wr_ddrb <= '0';
 wr_portc <= '0';
 wr_ddrc <= '0';
 wr_portd <= '0';
 wr_ddrd <= '0';
 if wr_io = '1' then
 case ioaddr is
 when 16#3f# => wr_sreg <= '1';
 when 16#3b# => wr_gimsk <= '1';
 when 16#39# => wr_timsk <= '1';
 when 16#38# => wr_tifr <= '1';
 when 16#35# => wr_mcucr <= '1';
 when 16#33# => wr_tccr0 <= '1';
 when 16#32# => wr_tcnt0 <= '1';
 when 16#18# => wr_portb <= '1';
 when 16#17# => wr_ddrb <= '1';
 when 16#15# => wr_portc <= '1';
 when 16#14# => wr_ddrc <= '1';
 when 16#12# => wr_portd <= '1';
 when 16#11# => wr_ddrd <= '1';
 when others =>
 end case;
 end if;
 end process;
 end iodecoder;
 
 
 
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