dsp56800e Freescale Semiconductor, Inc, dsp56800e Datasheet - Page 266

• Manufacturer Part Number: dsp56800e
• Description: 16-bit Digital Signal Controller Core
• Manufacturer: Freescale Semiconductor, Inc

Program Controller
8.6.3
Regular interrupt processing is supported in data-memory execution mode. The interrupt vector table and
all interrupt service routines must be copied to data memory because program memory is completely
disabled when data-memory execution mode is active. It is only necessary to provide interrupt vectors and
service routines for interrupts that will actually occur during data memory execution.
During the transition in and out of data-memory execution mode, interrupts must be disabled.
8.6.4
The following restrictions apply when programs are executed from data memory:
Instructions that perform one parallel move operation are allowed in this mode.
8-28
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Instructions that perform two reads from data memory are not permitted.
Instructions that access program memory are not permitted.
Interrupts must be disabled when data-memory execution mode is entered or exited.
Interrupts in Data-Memory Execution Mode
Restrictions on Data-Memory Execution Mode
The code that is used to exit data-memory execution mode must contain
the exact number of NOP instructions that is shown in Example 8-15 or
Example 8-16 on page 8-27. There can be no jumps or branches to
instructions within this sequence.
DSP56800E Core Reference Manual
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