Core Registers
A-26
ADSP-2126x SHARC Processor Hardware Reference
Interrupt Mask Pointer Register (IMASKP)
The
IMASKP
register is a non-memory-mapped, universal, system register
(
Ureg
and
Sreg
). Each bit in the
IMASKP
register corresponds to a bit with
the same name in the
IRPTL
registers. The
IMASKP
register field descrip-
tions are shown in
, and described in
. Shaded cells
indicate user programmable interrupts.
This register supports an interrupt nesting scheme that lets higher priority
events interrupt an ISR and keeps lower priority events from interrupting.
When interrupt nesting is enabled, the bits in the
IMASKP
register mask
interrupts that have a lower priority than the interrupt that is currently
being serviced. Other bits in this register unmask interrupts having higher
priority than the interrupt that is currently being serviced. Interrupt nest-
ing is enabled using
NESTM
in the
MODE1
register. The
IRPTL
register latches
a lower priority interrupt even when masked, and the processor responds
to that latched interrupt if it is later unmasked.
When interrupt nesting is disabled (
NESTM
= 0 in the
MODE1
register), the
bits in the
IMASKP
register mask all interrupts while an interrupt is cur-
rently being serviced. The
IRPTL
register still latches these interrupts even
when masked, and the processor responds to the highest priority latched
interrupt after servicing the current interrupt.
Summary of Contents for ADSP-21261 SHARC
Page 30: ...Contents xxx ADSP 2126x SHARC Processor Hardware Reference ...
Page 40: ...Register Diagram Conventions xl ADSP 2126x SHARC Processor Hardware Reference ...
Page 58: ...Differences From Previous SHARCs 1 18 ADSP 2126x SHARC Processor Hardware Reference ...
Page 112: ...Secondary Processing Element PEy 2 54 ADSP 2126x SHARC Processor Hardware Reference ...
Page 178: ...Summary 3 66 ADSP 2126x SHARC Processor Hardware Reference ...
Page 204: ...DAG Instruction Summary 4 26 ADSP 2126x SHARC Processor Hardware Reference ...
Page 322: ...Setting Up DMA 7 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 436: ...SPORT Programming Examples 9 86 ADSP 2126x SHARC Processor Hardware Reference ...
Page 521: ...ADSP 2126x SHARC Processor Hardware Reference 11 31 Input Data Port rts IDP_ISR end ...
Page 522: ...Input Data Port Programming Example 11 32 ADSP 2126x SHARC Processor Hardware Reference ...
Page 590: ...Timer Programming Examples 14 20 ADSP 2126x SHARC Processor Hardware Reference ...
Page 796: ...I O Processor Registers A 174 ADSP 2126x SHARC Processor Hardware Reference ...
Page 800: ...B 4 ADSP 2126x SHARC Processor Core Manual ...
Page 846: ...Index I 36 ADSP 2126x SHARC Processor Hardware Reference ...