| ??? 01/04/08 18:04 Read: times |
#149055 - Variable delay Responding to: ???'s previous message |
The place where I used that routine was indeed one of those 1% of the 1% of the 1% cases that you don't run into very often.
A pal and I were building a tester that needed to put out a couple of pulses with a certain delay between them, where the delay had to be adjustable over a certain range with as fine a resolution as we could come up with. We wound up using a 100 MHz SiLabs screamer, which gave us 10 ns resolution on the delay. 5 ns resolution would have been better, but we got by. I can't honestly say I ever thought about the caching issues, but I can say that the results we got were predictable and stable. Maybe reason was that the testing loop was so small and simple that the cache behaved the same way every time. Probably? -- Russ |
| Topic | Author | Date |
| Number of CPU cycle for 8051 function call | 01/01/70 00:00 | |
| Do it in assembler | 01/01/70 00:00 | |
| Delay functions | 01/01/70 00:00 | |
| A related trick | 01/01/70 00:00 | |
| Offset | 01/01/70 00:00 | |
| Offset | 01/01/70 00:00 | |
| Sure | 01/01/70 00:00 | |
| Over Drive? | 01/01/70 00:00 | |
| a refinement | 01/01/70 00:00 | |
| NOPs are so bad waste of space... | 01/01/70 00:00 | |
| waste of space... waste of time | 01/01/70 00:00 | |
| fixed delay | 01/01/70 00:00 | |
| Variable delay | 01/01/70 00:00 | |
| determinism of the cache | 01/01/70 00:00 | |
| there are no cache misses in 'linear code' | 01/01/70 00:00 | |
| I got only ONE cache miss... | 01/01/70 00:00 | |
| Old Keil Thread | 01/01/70 00:00 | |
| What about a Delay like this. | 01/01/70 00:00 | |
| No, it won't. | 01/01/70 00:00 | |
| Ok. | 01/01/70 00:00 | |
| also | 01/01/70 00:00 | |
| Also ... | 01/01/70 00:00 | |
| Actually... | 01/01/70 00:00 | |
| will. | 01/01/70 00:00 | |
| ANSI C | 01/01/70 00:00 | |
Keil option: Disable ANSI casts | 01/01/70 00:00 | |
| typo. | 01/01/70 00:00 |