April 2020
Intermediate to advanced
412 pages
9h 58m
English
Content preview from Embedded Programming with Modern C++ Cookbook
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8051 microcontroller interrupts
The 8051 microcontroller supports six interrupt sources – reset, two hardware interrupts, two timer interrupts, and a serial communication interrupt:
| Interrupt number | Description | Offset in bytes |
| Reset | 0 | |
| 0 | External interrupt INT0 | 3 |
| 1 | Timer 0 (TF0) | 11 |
| 2 | External interrupt INT1 | 19 |
| 3 | Timer 1 (TF1) | 27 |
| 4 | Serial | 36 |
The interrupt vector array is located at address 0; each entry except reset is 8 bytes in size. Though a minimal ISR can fit into 8 bytes, normally, the entries contain code that redirects execution to the actual ISR located elsewhere.
The reset entry is special. It is activated by the reset signal and immediately jumps to the address where the main program is located.
8051 defines a ...