ROM generator script for cos/sin

#!/usr/bin/env python

# -*- coding: utf-8 -*-

from __future__ import print_function

from __future__ import division

# Copyright (C) 2017, Elphel.inc.

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program 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 General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

#

'''

 Signed subpixel shifts in the range [-0.5,0.5) are converted to sign and [0,0.5] and both limits are fit to the same slot as

 the shift -0.5 :  cos((i+0.5)/16*pi), -sin((i+0.5)/16*pi) for i=0..7 is symmetrical around the center (odd for sine, even - cosine)

 ROM input MSB - 0- cos, 1 - sin,  3 LSB s - index (0..7). Signs for cos and sin are passed to DSPs

 shift               i    sin  ROM[9]     ROM A[8:3]   ROM A[2:0]   sign cos   sign sin

 1000000 (-0.5)     nnn    0     1         0           ~nnn          0         1

                    nnn    1     1         0            nnn          0         1

 1xxxxxx (<0)       nnn    s     s   -xxxxxx            nnn          0         1

 0000000 (==0)      nnn    0     0          0             0          0         0

                    nnn    1     0          0             1          0         0

 0xxxxxx (>0)       nnn    s     s    xxxxxx            nnn          0         0

'''

__author__ = "Andrey Filippov"

__copyright__ = "Copyright 2017, Elphel, Inc."

__license__ = "GPL"

__version__ = "3.0+"

__maintainer__ = "Andrey Filippov"

__email__ = "andrey@elphel.com"

__status__ = "Development"

import sys

import math

import os

import datetime

mclt_wnd_rom_path=  '../includes/mclt_rotator_rom.vh'

def create_with_parity (init_data,   # numeric data (may be less than full array

                        num_bits,    # number of bits in item, valid:  1,2,4,8,9,16,18,32,36,64,72

                        full_bram):  # true if ramb36, false - ramb18

    d = num_bits

    num_bits8 = 1;

    while d > 1:

        d >>= 1

        num_bits8 <<= 1

    bsize = (0x4000,0x8000)[full_bram]

    bdata = [0  for i in range(bsize)]

    sb = 0

    for item in init_data:

#        print(item)

        for bt in range (num_bits8):

            bdata[sb+bt] = (item >> bt) & 1;

        sb += num_bits8

    data = []

    for i in range (len(bdata)//256):

        d = 0;

        for b in range(255, -1,-1):

            d = (d<<1) +  bdata[256*i+b]

        data.append(d)

    data_p = []

    num_bits_p = num_bits8 >> 3

    sb = 0

    print ("num_bits=",num_bits)

    print ("num_bits8=",num_bits8)

    print ("num_bits_p=",num_bits_p)

    if num_bits_p:    

        pbsize = bsize >> 3    

        pbdata = [0  for i in range(pbsize)]

        for item in init_data:

            for bt in range (num_bits_p):

                pbdata[sb+bt] = (item >> (bt+num_bits8)) & 1;

            sb += num_bits_p

        for i in range (len(pbdata)//256):

            d = 0;

            for b in range(255, -1,-1):

                d = (d<<1) +  pbdata[256*i+b]

            data_p.append(d)

    return {'data':data,'data_p':data_p}

def print_params(data,

                 out_file_name,

                 comment=""): # text to add to the file header

    with open(out_file_name,"w") as out_file:

        print ("// Created with "+sys.argv[0], file=out_file)

        if comment:

            print (comment, file=out_file)

        for i, v in enumerate(data['data']):

            if v:

                print (", .INIT_%02X (256'h%064X)"%(i,v), file=out_file)

    #    if (include_parity):

        for i, v in enumerate(data['data_p']):

            if v:

                print (", .INITP_%02X (256'h%064X)"%(i,v), file=out_file)

def create_rotator(addr=10): # n - DCT and window size

    rom = []

    maxv=(1 << 17) - 1

    sin_a = 1 << (addr-1) # 512

    shft_offs = 3

    for _ in range(1 << addr):

        rom.append(0)

    for shft in range(1 <<(addr-4)):

        ashift = 1.0 * shft/(1 <<(addr-3))

        if shft == 0:

            ashift = 0.5

        for i in range(8):

            a = (i+0.5) * math.pi * ashift / 8

            rom[ i + (shft << shft_offs) + sin_a] = int(round(maxv*math.sin(a)))

            if shft > 0:

                rom[ i + (shft << shft_offs) + 0 * sin_a] = int(round(maxv*math.cos(a)))

            elif i == 0:

                rom[ i + (shft << shft_offs) + 0 * sin_a] = maxv

            elif i == 1:

                rom[ i + (shft << shft_offs) + 0 * sin_a] = 0 # not needed, just for clarity

    return rom

'''

Calculate ROM for MCLT fold indices:

A0..A1 - variant, folding to the same 8x8 sample

A2..A4 - sample column in folded 8x8 tile

A5..A7 - sample row in folded 8x8 tile

D0..D4 - pixel column in 16x16 tile

D5..D7 - pixel row in 16x16 tile

D8 -  negate for mode 0 (CC)

D9 -  negate for mode 1 (SC)

D10 - negate for mode 2 (CS)      

D11 - negate for mode 3 (SS)

'''

print_params(

    create_with_parity(create_rotator (), 18, False),

    os.path.abspath(os.path.join(os.path.dirname(__file__), mclt_wnd_rom_path)),

    "// MCLT rotator cos/sin values")

print ("MCLT rotator cos/sin data is written to %s"%(os.path.abspath(os.path.join(os.path.dirname(__file__), mclt_wnd_rom_path))))