Name	Direction	Width	Purpose
rst	input		active-high asynchronous reset signal
clk	input		clock
cen	input		clock enable.
sel	input	2	selects the data rate
din	input	4	input data
sound	output	12	signed sound output

Usage

This is a pin-to-pin compatible module with OKI MSM5205. If you are just going to use it on a retro core you don't need to know the internals of it just hook it up and be sure that the effective clock rate, i.e. clk&cen signal, is the intended 384kHz (or whatever your system needs).

If you hear a periodic noise when there should be no output, check whether your target system was leaving the MSM5205 halted at reset when no output was needed. If The part is not reset it will keep processing the output and a constant 0 input will produce a repetitive noise.

FPGA arcade cores using this module:

Double Dragon, by the same author
Tora e no michi, by the same author