MyHDL:无法将Signal.intbv.max转换为VHDL语言

Question

我是新接触MyHDL和MyHDL的，所以我从把旧的VHDL项目转换成python开始。这个项目是一个vga计时器，可以接受任何宽度，高度和频率(考虑到他们实际上与显示器工作)。由于以下语句，它无法成功转换为VHDL或Verilog：

h_count.val.max  # line 30
v_count.val.max  # line 33

我可以很好地打印它们的值，这样它们肯定会计算成整数，但是如果我用它们的文字值替换它们，那么它就可以正确地转换。我在myhdl问题跟踪器中找不到任何关于这个问题的东西，但我不想因为一个新手的错误而添加一个错误的问题。有没有合适的方式来使用Signal.val.max，或者我应该避免使用它？下面是完整的代码：

from myhdl import Signal, intbv, always_comb, always, toVHDL


def vga_timer(clk, x, y, h_sync, v_sync, vidon, width=800, height=600, frequency=72,
          left_buffer=0, right_buffer=0, top_buffer=0, bottom_buffer=0):
    # load vga constants by resolution
    resolution = (width, height, frequency)
    supported_resolutions = {(640, 480, 60): (16, 96, 48, 10, 2, 33, 0),
                         (800, 600, 60): (40, 128, 88, 1, 4, 23, 1),
                         (800, 600, 72): (56, 120, 64, 37, 6, 23, 1),
                         (1024, 768, 60): (24, 136, 160, 3, 6, 29, 0),
                         (1280, 720, 60): (72, 80, 216, 3, 5, 22, 1),
                         (1920, 1080, 60): (88, 44, 148, 4, 5, 36, 1)}
    assert resolution in supported_resolutions, "%ix%i @ %ifps not a supported resolution" % (width, height, frequency)
    screen_constants = supported_resolutions.get(resolution)

    # h for horizontal variables and signals, v for vertical constants and signals
    h_front_porch, h_sync_width, h_back_porch, v_front_porch, v_sync_width, v_back_porch, polarity = screen_constants

    h_count = Signal(intbv(0, 0, width + h_front_porch + h_sync_width + h_back_porch))
    v_count = Signal(intbv(0, 0, height + v_front_porch + v_sync_width + v_back_porch))

    print(h_count.val.max)
    print(v_count.val.max)

    @always(clk.posedge)
    def counters():
        h_count.next = h_count + 1
        v_count.next = v_count
        if h_count == 1040 - 1:  # h_count.val.max - 1:
            h_count.next = 0
            v_count.next = v_count + 1
            if v_count == 666 - 1:  # v_count.val.max - 1:
                v_count.next = 0

    # determines h_sync and v_sync
    @always_comb
    def sync_pulses():
        h_sync_left = width - left_buffer + h_front_porch
        h_sync_right = h_sync_left + h_sync_width
        h_sync.next = polarity
        if h_sync_left <= h_count and h_count < h_sync_right:
             h_sync.next = not polarity

        v_sync_left = height - top_buffer + v_front_porch
        v_sync_right = v_sync_left + v_sync_width
        v_sync.next = polarity
        if v_sync_left <= v_count and v_count < v_sync_right:
            v_sync.next = not polarity

    @always_comb
    def blanking():
        vidon.next = 0
        if h_count < width - left_buffer - right_buffer and v_count < height - top_buffer - bottom_buffer:
            vidon.next = 1

    @always_comb
    def x_y_adjust():
        # x and y are only used when vidon = 1. during this time x = h_count and y = v_count
        x.next = h_count[len(x.val):]
        y.next = v_count[len(y.val):]

    return counters, sync_pulses, blanking, x_y_adjust

width = 800
height = 600
frequency = 72

clk = Signal(bool(0))
x = Signal(intbv(0)[(width-1).bit_length():])
y = Signal(intbv(0)[(height-1).bit_length():])
h_sync = Signal(bool(0))
v_sync = Signal(bool(0))
vidon = Signal(bool(0))

vga_timer_inst = toVHDL(vga_timer, clk, x, y, h_sync, v_sync, vidon, width, height, frequency)

任何关于我的代码的建议也是受欢迎的。

Answer 1

你现在可能已经发现了这一点，但是如果你想要可转换的代码，你不能使用信号质量(最小，最大，位数等)。在组合或顺序块中。不过，您可以在这些块之外的常量赋值中使用它们。因此，如果您使用这些语句而不是print语句：h_counter_max = h_count.val.max - 1 v_counter_max = v_count.val.max - 1，则可以在测试中的第30和33行使用h_counter_max和v_counter_max。

Answer 2

可以在最新版本中使用min、max属性。