Texas Instruments MSP430x1xx Computer Hardware User Manual


 
Instruction Set
3-40
RISC 16−Bit CPU
* EINT Enable (general) interrupts
Syntax EINT
Operation 1 GIE
or
(0008h .OR. SR −> SR / .src .OR. dst −> dst)
Emulation BIS #8,SR
Description All interrupts are enabled.
The constant #08h and the status register SR are logically ORed. The result
is placed into the SR.
Status Bits Status bits are not affected.
Mode Bits GIE is set. OSCOFF and CPUOFF are not affected.
Example The general interrupt enable (GIE) bit in the status register is set.
; Interrupt routine of ports P1.2 to P1.7
; P1IN is the address of the register where all port bits are read. P1IFG is the address of
; the register where all interrupt events are latched.
;
PUSH.B &P1IN
BIC.B @SP,&P1IFG ; Reset only accepted flags
EINT ; Preset port 1 interrupt flags stored on stack
; other interrupts are allowed
BIT #Mask,@SP
JEQ MaskOK ; Flags are present identically to mask: jump
......
MaskOK BIC #Mask,@SP
......
INCD SP ; Housekeeping: inverse to PUSH instruction
; at the start of interrupt subroutine. Corrects
; the stack pointer.
RETI
Note: Enable Interrupt
The instruction following the enable interrupt instruction (EINT) is always
executed, even if an interrupt service request is pending when the interrupts
are enable.