Question

I’m planning on making a clock. An actual clock, not something for Windows. However, I would like to be able to write most of the code now. I’ll be using a PIC16F628A to drive the clock, and it has a timer I can access (actually, it has 3, in addition to the clock it has built in). Windows, however, does not appear to have this function. Which makes making a clock a bit hard, since I need to know how long it’s been so I can update the current time. So I need to know how I can get a pulse (1Hz, 1KHz, doesn’t really matter as long as I know how fast it is) in Windows.

Answer 1

There are many timer objects available in Windows. Probably the easiest to use for your purposes would be the Multimedia Timer, but that’s been deprecated. It would still work, but Microsoft recommends using one of the new timer types.

I’d recommend using a threadpool timer if you know your application will be running under Windows Vista, Server 2008, or later. If you have to support Windows XP, use a Timer Queue timer.

There’s a lot to those APIs, but general use is pretty simple. I showed how to use them (in C#) in my article Using the Windows Timer Queue API. The code is mostly API calls, so I figure you won’t have trouble understanding and converting it.

The LARGE_INTEGER is just an 8-byte block of memory that’s split into a high part and a low part. In assembly, you can define it as:

MyLargeInt equ $
MyLargeIntLow dd 0
MyLargeIntHigh dd 0

If you’re looking to learn ASM, just do a Google search for [x86 assembly language tutorial]. That’ll get you a whole lot of good information.