4.1. Main¶
Execution starts in the main.main function. This function must have the void return type and must not have any arguments.
Execution starts in the main.main function. This function must have the void return type and must not have any arguments.
Interrupt handlers are functions defined in the interrupts module and start with handler_. The name following handler_ must be one of the handler names in the table below. Interrupt handlers must have the void return type and must not have any arguments.
Defined interrupt handlers create an appropriate interrupt vector. This does not enable the interrupts; see the hardware documentation for details about this.
To include the interrupts module for compilation, it is recommended to create an “enable interrupts” function within the interrupts module and call this function from another module.
| Interrupt | Handler name | Vector |
|---|---|---|
| IE0 | IE0 | 0x03 |
| TF0 | TF0 | 0x0B |
| IE1 | IE1 | 0x13 |
| TF1 | TF1 | 0x1B |
| RI, TI | RI_TI | 0x23 |
| TF2 | TF2 | 0x2B |
| IADC | IADC | 0x43 |
| IE2 | IE2 | 0x4B |
| TRF, BCERR | TRF_BCERR | 0x53 |
| CC2P | CC2P | 0x5B |
| CCnF, CCnR (n=0,1,2) | CCnF_CCnR | 0x63 |
| CT1FP, CT1FC | CT1FP_CT1FC | 0x6B |
| Power down interrupt | PDI | 0x7B |
The SC compiler predefines the sfr module with data fields pointing to the special function registers. In the current version of the SC compiler, this contains all special function registers found in the Siemens C504. This is a superset of the special function registers found in the Intel 8051, although some are named subtly different. In a future version, you can specify the specific microcontroller you’re compiling for, so that only that microcontroller’s special function registers are available.
If you need to use a special function register not provided by the sfr module, you can define it (in another module) like this:
addr internal mysfr = 0xFF;
The SC compiler defines the compilerservices module. Normally, this module should never be used. It provides functions that are easy in assembly code, but impossible to do with normal language constructs.
reti() is a function that contains one instruction: RETI. This function is not needed to return from interrupt handlers; interrupt handlers always end with a RETI instruction. This function is only needed if you abnormally exit an interrupt handler.
reset() is a function that resets program execution while keeping memory contents. When called, the stack pointer is reset to its initial value, and jumps to the start of main.main(). If used within an interrupt handler, call reti() before calling reset(). reset() could be useful in ‘fast abort’ situations, where restarting and reinitializing is faster or simpler than executing stop actions at every layer in the call stack.