--****************************************************************************************************
-- Constants for ARM core
-- Designed by Ruslan Lepetenok
-- Modified 30.01.2003
--****************************************************************************************************
library	IEEE;
use IEEE.std_logic_1164.all;

package	ARMPackage is

-- ARM core modes (CPSR [4:0])
constant CUserMode   : std_logic_vector(4 downto 0) := "10000";
constant CFIQMode    : std_logic_vector(4 downto 0) := "10001";
constant CIRQMode    : std_logic_vector(4 downto 0) := "10010";
constant CSVCMode    : std_logic_vector(4 downto 0) := "10011";
constant CAbortMode  : std_logic_vector(4 downto 0) := "10111";
constant CUndefMode  : std_logic_vector(4 downto 0) := "11011";
constant CSystemMode : std_logic_vector(4 downto 0) := "11111";	

constant CPSRInitVal : std_logic_vector(31 downto 0) := (31 downto 8 => '0')&"110"&CSVCMode;

-- Exception vector adressses
constant CExcAdrUndefined : std_logic_vector(31 downto 0) := x"0000_0004";
constant CExcAdrSWI       : std_logic_vector(31 downto 0) := x"0000_0008";
constant CExcAdrPrfAbt    : std_logic_vector(31 downto 0) := x"0000_000C";
constant CExcAdrDtAbt     : std_logic_vector(31 downto 0) := x"0000_0010";
constant CExcAdrIRQ       : std_logic_vector(31 downto 0) := x"0000_0018";
constant CExcAdrFIQ       : std_logic_vector(31 downto 0) := x"0000_001C";

-- Bus transaction types (TRANS[1:0])
constant CTT_I : std_logic_vector(1 downto 0) := "00"; -- Internal cycle 
constant CTT_C : std_logic_vector(1 downto 0) := "01"; -- Coprocessor register transfer cycle	
constant CTT_N : std_logic_vector(1 downto 0) := "10"; -- Nonsequential cycle	
constant CTT_S : std_logic_vector(1 downto 0) := "11"; -- Sequential cycle

-- Bus transaction sizes (SIZE[1:0])
constant CTS_B  : std_logic_vector(1 downto 0) := "00"; -- Byte 
constant CTS_HW : std_logic_vector(1 downto 0) := "01"; -- Halfword (16 bit)
constant CTS_W  : std_logic_vector(1 downto 0) := "10"; -- Word(32 bit)	

-- TBD (depends on the address multiplexer structure)
constant CPCInitVal  : std_logic_vector(31 downto 0) := x"0000_0000"; 

-- Symbolic register names
constant CR_PC  : std_logic_vector(3 downto 0) := "1111"; -- PC(R15)
constant CR_LR  : std_logic_vector(3 downto 0) := "1110"; -- LR(R14)

-- Thumb
constant CThumbImp : boolean := TRUE;

-- Don't care value
constant CDnCr : std_logic := '0';

end;