Incorrect Calculation Formula for N in Audio Regeneration

[kazuma-t]

When using a resolution of 720p and a sampling rate of 44.1kHz, the current calculation formula generates an excessively large value.

The diff with the correct calculation formula is as follows:

--- a/src/hdmi/audio_clock_regeneration_packet.sv
+++ b/src/hdmi/audio_clock_regeneration_packet.sv
@@ -16,7 +16,7 @@ module audio_clock_regeneration_packet
 );

 // See Section 7.2.3, values derived from "Other" row in Tables 7-1, 7-2, 7-3.
-localparam bit [19:0] N = AUDIO_RATE % 125 == 0 ? 20'(16 * AUDIO_RATE / 125) : AUDIO_RATE % 225 == 0 ? 20'(196 * AUDIO_RATE / 225) : 20'(AUDIO_RATE * 16 / 125);
+localparam bit [19:0] N = AUDIO_RATE % 125 == 0 ? 20'(16 * AUDIO_RATE / 125) : AUDIO_RATE % 225 == 0 ? 20'(32 * AUDIO_RATE / 225) : 20'(AUDIO_RATE * 16 / 125);

 localparam int CLK_AUDIO_COUNTER_WIDTH = $clog2(N / 128);
 localparam bit [CLK_AUDIO_COUNTER_WIDTH-1:0] CLK_AUDIO_COUNTER_END = CLK_AUDIO_COUNTER_WIDTH'(N / 128 - 1);

The modified calculation formula will correctly calculate the value of N, ensuring it falls within the recommended range.

[sameer]

Thanks for finding this, I'll update the repo shortly :)