Texas Instruments MSP430x1xx User Manual
Page 379
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Instruction Set Overview
B-29
Instruction Set Description
* EINT
Enable (general) interrupts
Syntax
EINT
Operation
1
→
GIE
or
(0008h .OR. SR –> SR / .NOT.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
N: Not affected
Z: Not affected
C: Not affected
V: 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 port P0.2 to P0.7
; The interrupt level is the lowest in the system
; P0IN is the address of the register where all port bits are read. P0IFG is the address of
; the register where all interrupt events are latched.
;
PUSH.B
&P0IN
BIC.B
@SP,&P0IFG
; Reset only accepted flags
EINT
; Preset port 0 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.