| ??? 02/03/09 11:38 Read: times |
#161989 - 40ns is a very short time Responding to: ???'s previous message |
When you set the port high, it will stay high indefinitely. You must change the port back to low again to toggle it.
Your crystal is 11MHz. If the processor does one instruction for each crystal tick it will take about 90ns for each instruction. Generating a 40ns pulse then might not be so easy. You can use external logic that will produce a 40ns pulse whenever a port pin switches from low to high. The complexity of such logic will depend on how important the 40ns time is. |
| Topic | Author | Date |
| what is the signal freuency on all ports of at89c52/51 | 01/01/70 00:00 | |
| minimum pule is 1086 nanoseconds. | 01/01/70 00:00 | |
| Buzz! | 01/01/70 00:00 | |
| 40ns is a very short time | 01/01/70 00:00 | |
| You need a faster MCU | 01/01/70 00:00 | |
| the fastest '51 | 01/01/70 00:00 | |
| 80ns ? | 01/01/70 00:00 | |
| Sorry about that ... | 01/01/70 00:00 | |
| Still not known if single pulse or pulse train | 01/01/70 00:00 | |
| Where there's a will ... | 01/01/70 00:00 | |
| Timer or PCA | 01/01/70 00:00 | |
| repeat earlier question with clarity | 01/01/70 00:00 | |
| Timing can't be discussed when C is involved | 01/01/70 00:00 | |
| Think about it | 01/01/70 00:00 | |
| Supplementary question... | 01/01/70 00:00 | |
At first blush . . . | 01/01/70 00:00 |