----------------------------------------------------------------------------------
-- Company: 
-- Engineer: Professor Jim Plusquellic
-- 
-- Create Date:
-- Design Name: 
-- Module Name:    DataTypes_pkg - Behavioral 
-- Project Name: 
-- Target Devices: 
-- Tool versions: 
-- Description: 
--
-- Dependencies: 
--
-- Revision: 
-- Revision 0.01 - File Created
-- Additional Comments: 
--
----------------------------------------------------------------------------------

library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
use IEEE.NUMERIC_STD.all;

package DataTypes_pkg is

-- We represent numbers in FIXED-POINT format, with 12-bit integer portion of the 16-bit number stored in the PN BRAM. 
-- The fractional component is given by 'PRECISION' and the sum is PN_SIZE_NB. PN_SIZE_LB needs to be able to count 
-- to PN_SIZE_NB.
   constant PN_NUMBITS_NB: integer := 12;
   constant PN_PRECISION_NB: integer := 4;
   constant PN_SIZE_LB: integer := 4;
   constant PN_SIZE_NB: integer := PN_NUMBITS_NB + PN_PRECISION_NB;

   constant BYTE_SIZE_LB: integer := 3;
   constant BYTE_SIZE_NB: integer := 8;

   constant WORD_SIZE_LB: integer := 4;
   constant WORD_SIZE_NB: integer := 16;

-- BRAM SIZES: PNL is currently 8192 bytes with 16-bit words. 
   constant PNL_BRAM_ADDR_SIZE_NB: integer := 13;
   constant PNL_BRAM_DBITS_WIDTH_LB: integer := PN_SIZE_LB;
   constant PNL_BRAM_DBITS_WIDTH_NB: integer := PN_SIZE_NB; 
   constant PNL_BRAM_NUM_WORDS_NB: integer := 2**PNL_BRAM_ADDR_SIZE_NB;

-- Largest positive (signed) value for PNs is 1023.9375 which is in binary 01111111111.1111, BUT AS a integer binary value with no 
-- decimal place, it is 16383 (0011111111111111) (note, we have 16-bit for the word size now).
   constant LARGEST_POS_VAL: integer := 16383;

-- My largest negative value is -1023.9375 or 110000000000.0001, AND as a integer binary value, -16383
   constant LARGEST_NEG_VAL: integer := -16383;

-- We store the raw data in the upper half of memory (locations 4096 to 8191). 
   constant PN_BRAM_BASE: integer := PNL_BRAM_NUM_WORDS_NB/2;
   constant PN_UPPER_LIMIT: integer := PNL_BRAM_NUM_WORDS_NB;

-- The distribution starts at the mid-point in the lower half of the BRAM (2048 to 4095)
   constant DIST_BRAM_OFFSET: integer := (PNL_BRAM_NUM_WORDS_NB/2)/2;

end DataTypes_pkg;