| ??? 04/11/07 08:58 Read: times |
#136962 - datasheet Responding to: ???'s previous message |
Chen,
look into the datasheet, chapter Interrupt Priority Structure. There are two different meanings of "priority" in '51: - priority set in IP (and in this derivative also IPA) SFR (allowing interrupts with higher priority to interrupt a currently executed interrupt with lower priority) - order of "polling", determining, which interrupt will be executed first if more interrupts are pending the datasheet then said:
If two interrupts of different priority occur simultaneously, the high priority level request is serviced.
If requests of the same priority are received simultaneously, an internal polling sequence determines which request is serviced. Thus, within each priority level, there is a second priority structure determined by the polling sequence. So, in your case, if you don't explicitly set either priority bit respective to UART0 and TIMER0 in IP, or set it for both, the timer interrupt will be executed first. Btw., this is basic 8051 topic, covered also by the "bible". Jan Waclawek |
| Topic | Author | Date |
| two interrupts request at the same time | 01/01/70 00:00 | |
| datasheet | 01/01/70 00:00 | |
| right,but | 01/01/70 00:00 | |
| error? what kind of error? | 01/01/70 00:00 | |
| not reset,in debug PC don't change any more | 01/01/70 00:00 | |
| Sounds like an atomicity problem | 01/01/70 00:00 | |
| Maybe an event gets lost | 01/01/70 00:00 | |
| initialization sequencing | 01/01/70 00:00 | |
| a rare bug.... | 01/01/70 00:00 | |
Interupts | 01/01/70 00:00 |