Unformatted text preview: ion steps: Estimate run times. Estimate timing constraints. Find scheduling. Run Times CDT, th = 1 s. Time is small because it only has to increment a variable and, sometimes, read a wobble. SPEED, th = 5 s. Must compute speed and update a table. Checking for table-length over ow and other conditions results in the longer run time. SPRAY, th = 50 s. In addition to adjusting actuators must set next timer interrupt. It might have to do some computation to determine when the next timer interrupt should be. wobble, run time 500 ms. 3 EE 4770 Lecture Transparency. Formatted 15:15, 26 April 1996 from hw.95.05.sol. 3 4 4 Timing Constraints
Suppose maximum spin speed is 1200 RPM. Suppose CDT has 1024 marks. Then minimum period for CDT is 49 s. Reasonable assumption: response must occur before next event. Constraint: Normal:Mark ,! CtrInc 49 s, where event Mark occurs when a mark passes under mark readers in the CDT, and response CtrInc occurs when CDT nishes. Similarly, for speed: Normal:Speed ,! Cntr 49 s, w...
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- Fall '99
- Trigraph, Central processing unit, Interrupt, CPU time, Priority level, Lecture Transparency