Global Enable/Disable For Interrupts - Analog Devices adsp-2100 Manual

ICNTL Interrupt Nesting Enable bit = 0 (nesting disabled)
Interrupt IMASK contents before IMASK contents entering
level serviced (pushed on stack)
0 (low)
ijklmn
1
ijklmn
2
ijklmn
3
ijklmn
4
ijklmn
5 (high)
ijklmn
ICNTL Interrupt Nesting Enable bit = 1 (nesting enabled)
Interrupt IMASK contents before IMASK contents entering
level serviced (pushed on stack)
0 (low)
ijklmn
1
ijklmn
2
ijklmn
3
ijklmn
4
ijklmn
5 (high)
ijklmn
("ijklmn" represents any pattern of ones and zeroes)
Table 3.8 IMASK Entering Interrupt Service Routines (ADSP-2101 example)

3.4.2.3 Global Enable/Disable for Interrupts

Global interrupt enable and disable instructions are available on the
ADSP-2171, ADSP-2181, and ADSP-21msp58/59 processors:
ENA INTS;
DIS INTS;
Interrupts are enabled by default after reset. The DIS INTS instruction
causes all interrupts (including powerdown) to be masked out regardless
of the contents of IMASK. The ENA INTS instruction allows all
unmasked interrupts to be serviced again.
Disabling interrupts does not affect serial port autobuffering.
Program Control
interrupt service routine
000000
000000
000000
000000
000000
000000
interrupt service routine
ijklm0
ijkl00
ijk000
ij0000
i00000
000000
3
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