| ??? 01/17/12 17:21 Read: times |
#185538 - what you think does not cause interrupts Responding to: ???'s previous message |
many misunderstandings re '51 interrupts come from the belief that things directly cause nterrupts, they do not.
neither the UART nor the SPI causes an interrupt. Both just set an "interrupt request flag". Then when the processor is ready (done with current instruction, not interrupts higher or current priority running) it will check the flags and decide if/which interrupt to take. thus for a shared interrupt: when coming out of the interrupt it will check the flags so if e.g. the SPI flag get set during asn UART interrupt, the SPI interrupt will then be executed. Erik |
| Topic | Author | Date |
| Shared interrupts. | 01/01/70 00:00 | |
| what you think does not cause interrupts | 01/01/70 00:00 | |
| You will not lose anything. | 01/01/70 00:00 | |
no surprise | 01/01/70 00:00 |