buf_fifo.py

#!/usr/bin/env python
# coding=utf-8


from myhdl import *
from math import *
from ram import *

class buf_fifo_int_in(object):

    def __init__(self,pixel_bits = 24):

        self.pixel_bits=pixel_bits

        """HOST PROG"""
        self.img_size_x=Signal(intbv(0)[16:])
        self.img_size_y=Signal(intbv(0)[16:])
        self.sof=Signal(bool(0))

        """HOST DATA"""
        self.iram_wren=Signal(bool(0))
        self.iram_wdata=Signal(intbv(0)[pixel_bits:])

        """FDCT"""
        self.fdct_fifo_rd=Signal(bool(0))



class buf_fifo_int_out(object):

    def __init__(self,pixel_bits = 24):

        self.pixel_bits=pixel_bits

        """HOST DATA"""
        self.fifo_almost_full=Signal(bool(0))

        """FDCT"""
        self.fdct_fifo_q=Signal(intbv(0)[pixel_bits:])
        self.fdct_fifo_hf_full=Signal(bool(0))


@block
def buf_fifo(in_sig,out_sig,clk,rst,extra_lines,pixel_bits,num_lines,max_line_width):



    num_lines = 8 + extra_lines

    pixel_cnt,line_cnt=[Signal(intbv(0)[16:]) for _ in range(2)]

    ramq,ramd=[Signal(intbv(0)[pixel_bits:]) for _ in range(2)]
    ramenw=Signal(bool(0))
    ramwaddr,ramraddr,ramwaddr_d1=[Signal(intbv(0)[log(max_line_width*num_lines,2):]) for _ in range(3)]

    pix_inblk_cnt,pix_inblk_cnt_d1=[Signal(intbv(0)[4:]) for _ in range(2)]
    line_inblk_cnt=Signal(intbv(0)[3:])

    read_block_count,read_block_count_d1,write_block_cnt=[Signal(intbv(0)[13:]) for _ in range(3)]

    ramaddr_int,raddr_base_line=[Signal(intbv(0)[(16 + log(num_lines,2)):]) for _ in range(2)]
    raddr_tmp=Signal(intbv(0)[16:])

    line_lock,memwr_line_cnt,memrd_line=[Signal(intbv(0)[log(num_lines,2):]) for _ in range(3)]

    memrd_offs_cnt=Signal(intbv(0)[log(num_lines+1,2)])

    wr_line_idx,rd_line_idx=[Signal(intbv(0)[16:]) for _ in range(2)]

    image_write_end=Signal(bool(0))

    sub_ram=RAM(ramq,ramd,ramraddr,ramwaddr_d1,ramenw,clk,log(max_line_width*num_lines,2),pixel_bits)


    """Register ram data input"""
    @always_seq(clk.posedge,rst)
    def data_reg():
        ramd.next=in_sig.iram_wdata
        ramenw.next=in_sig.iram_wren

    """Resolve RAM write address"""
    @always_seq(clk.posedge,rst)
    def ram_addr_get():
        ramwaddr_d1.next=ramwaddr
        if in_sig.iram_wren == 1:
            if pixel_cnt == in_sig.img_size_x -1:
                pixel_cnt.next=0
                wr_line_idx.next=wr_line_idx+1
                if wr_line_idx  == in_sig.img_size_y:
                    image_write_end.next=1
                if memwr_line_cnt == num_lines -1:
                    memwr_line_cnt.next=0
                    ramwaddr.next=0
                else:
                    memwr_line_cnt.next=memwr_line_cnt + 1
                    ramwaddr.next=ramwaddr + 1
            else:
                pixel_cnt.next = pixel_cnt +1
                ramwaddr.next=ramwaddr + 1
        if in_sig.sof ==1:

            pixel_cnt.next=0
            ramwaddr.next=0
            memwr_line_cnt.next=0
            wr_line_idx.next=0
            image_write_end.next=0

    """FIFO half full/almost full flag generation"""
    @always_seq(clk.posedge,rst)
    def hf_af_flag():

        if rd_line_idx + 8 <= wr_line_idx:
            out_sig.fdct_fifo_hf_full.next=1
        else:
            out_sig.fdct_fifo_hf_full.next=0

        out_sig.fifo_almost_full.next=0

        if wr_line_idx ==  rd_line_idx + num_lines - 1:
            if pixel_cnt >= in_sig.img_size_x -1:
                out_sig.fifo_almost_full.next=1
        elif wr_line_idx > rd_line_idx + num_lines -1:
            out_sig.fifo_almost_full.next=1


    """ memrd_offs_cnt is used for the extra 8 lines to ensure that the block which is read will be in correct position in memory"""

    """Read side"""
    @always_seq(clk.posedge,rst)
    def read_side():

        pix_inblk_cnt_d1.next = pix_inblk_cnt
        read_block_count_d1.next = read_block_count

        if in_sig.fdct_fifo_rd == 1:
            if pix_inblk_cnt == 7:
                pix_inblk_cnt.next = 0

                if line_inblk_cnt == 7 :
                    line_inblk_cnt.next=0

                    if read_block_count == in_sig.img_size_x//num_lines -1:
                        read_block_count.next=0
                        rd_line_idx.next = 0
                        if memrd_offs_cnt + 8 >= num_lines - 1:
                            memrd_offs_cnt.next = memrd_offs_cnt + 8 - num_lines
                        else:
                            memrd_offs_cnt.next = memrd_offs_cnt + 8
                    else:
                        read_block_count.next=read_block_count + 1
                else:
                    line_inblk_cnt.next=line_inblk_cnt + 1
            else:
                pix_inblk_cnt.next  = pix_inblk_cnt + 1


        if memrd_offs_cnt + line_inblk_cnt > num_lines -1:

            memrd_line.next=memrd_offs_cnt + line_inblk_cnt - num_lines
        else:
            memrd_line.next=memrd_offs_cnt + line_inblk_cnt

        if in_sig.sof==1:

            memrd_line.next=0
            memrd_offs_cnt.next=0
            read_block_count.next=0
            pix_inblk_cnt.next=0
            pix_inblk_cnt.next=0
            line_inblk_cnt.next=0
            rd_line_idx.next=0

    """Generate RAM data output"""
    @always_comb
    def ram_out():

        out_sig.fdct_fifo_q.next = ramq
        ramraddr.next = ramaddr_int

    """Resolve RAM read address"""
    @always_seq(clk.posedge,rst)
    def ram_read_addr():


        raddr_base_line.next = memrd_line *in_sig. img_size_x
        raddr_tmp.next =  ConcatSignal(read_block_count_d1,"000") + pix_inblk_cnt_d1

        ramaddr_int.next = raddr_tmp + raddr_base_line

    return sub_ram,instances()

def convert():

    clk=Signal(bool(0))
    rst=ResetSignal(val=1,active=True,async=False)

    inputs=buf_fifo_int_in()
    outputs=buf_fifo_int_out()

    inst=buf_fifo(inputs,outputs,clk,rst,0,24,8,640)
    inst.convert(hdl='Verilog')



convert()