a VHDL version of the Intel 8254 timer.
Note: uses a synchronous (Wishbone) processor interface, rather than an asynchronous of the Intel 8254.
Design assumes asynchronous interface/counter clocks – includes Boolean generics (for each counter) if the same clock is used for interface and counter, or if the clocks are synchronous (different frequency, but with aligned rising edges)
Uses parts from the gh_vhdl_library project
added version with AMBA APB interface 16 Aug 2008