Atmel CAVR-4 Manual De Usuario

CAVR-4

Part 2. Compiler reference

This chapter gives reference information about the intrinsic functions.

The intrinsic functions provide direct access to low-level processor operations 

and can be very useful in, for example, time-critical routines. The intrinsic 

functions compile into inline code, either as a single instruction or as a short 

sequence of instructions.

The following table summarizes the intrinsic functions:

_ _delay_cycles

Inserts a time delay

_ _disable_interrupt

Disables interrupts

_ _enable_interrupt

Enables interrupts

_ _extended_load_program_memory

Returns one byte from code memory

_ _fractional_multiply_signed

Generates an FMULS instruction

_ _fractional_multiply_signed_

  with_unsigned

Generates an FMULSU instruction

_ _fractional_multiply_unsigned

Generates an FMUL instruction

_ _indirect_jump_to

Generates an IJMP instruction

_ _insert_opcode

Assigns a value to a processor register

_ _load_program_memory

Returns one byte from code memory

_ _multiply_signed

Generates a MULS instruction

_ _multiply_signed_with_unsigned

Generates a MULSU instruction

_ _multiply_unsigned

Generates a MUL instruction

_ _no_operation

Generates a NOP instruction

_ _require

Sets a constant literal

_ _restore_interrupt

Restores the interrupt flag

_ _reverse

Reverses the byte order of a value

_ _save_interrupt

Saves the state of the interrupt flag

_ _segment_begin

Returns the start address of a segment