Texas Instruments TMS320C28x, Reference Manual

Page: 288 / 695

LRETE
6-131
LRETE Long Return and Enable Interrupts
SYNTAX OPTIONS OPCODE OBJMODE RPT CYC
LRETE
0111 0110 0001 0000
X − 8
Operands None
Description Long return and enable interrupts. The return address is popped, from the
software stack into the PC, in two 16-bit operations. Next, the global interrupt
flag (INTM) is cleared. This enables global maskable interrupts:
SP = SP – 1;
temp(31:16) = [SP];
SP = SP − 1;
temp(15:0) = [SP];
PC = temp(21:0);
INTM = 0;
Flags and
Modes
INTM This instruction enables interrupts by clearing the INTM bit.
Repeat This instruction is not repeatable. If this instruction follows the RPT
instruction, it resets the repeat counter (RPTC) and executes only once.
Example
; Standard function call of FuncA. Disable interrupts on entry and
; enable interrupts on exit:
LC FuncA ; Call FuncA, return address on stack
.
.
FuncA: ; Function A:
SETC INTM ; Disable interrupts
.
.
LRETE ; Return from address on stack,
; Enable interrupts