Thoughts on Programming | Cypress Semiconductor
Thoughts on Programming
March 23, 2010
I have spent most of my career in the design and development of micro-controller based systems. These designs all were real time applications. The other programming I have done has been with tool generation or modeling. These were not real time applications.
I find that the new college grads (NCG)s learned how to program, most likely on a PC, by the computer science department and real time was never really an issue. I am surprised the number of them that have never calculated an interrupts time. I have seen interrupt based systems that fail when a particular bunch of operations are being run. The solution usually is a quick conditional to not let an offending interrupt run immediately. (You don’t know why it fails, but you make sure the condition won’t happen) You only have 100% of the CPU. It seems to me that you would want to know just how much time you need for each operation.
I have always felt the engineers would be better served if they learned “C”, in the EE department, writing for a small micro, doing real time applications. Some schools no longer teach C but go directly to Java. In the PSoC Lab book I wrote, the underling theme project was an I2C controlled temperature compensated fan. The programming was in C.
Real time applications have to worry about determinism, interrupt latency, min max and average interrupt service time. Non real time programmer may heavily depend on interrupts. This isn’t the case with real time systems.
It becomes quite apparent when engineers first attempt to collect Cap Sense data via the I2C that these ideas are not well understood.
Side note: I am finding NCGs coming out of school that specialized in Digital Signal Processing and have only built filters in MatLab. Never touched a real DSP.