Embedded Systems Design, 2nd Edition

Real-time without a RTOS 413

read to one of the serial port registers and tests a bit to the existing

instruction flow. If characters are detected these are easily re-

moved before operation but as this should only happen during an

engine shutdown and restart where timing accuracy is not abso-

lutely essential. Indeed, the data logger marks the data log to

indicate that an error has occurred. The sample data collection will

also time out if no data is received. This is detected and again the

sample aborted and a marker inserted to indicate that a timeout

has occurred.

Program listing

The rest of this chapter contains the logging program,

complete with comments ...