ST STM32F3 Series Programming Manual page 223

PM0214
DISFOLD
Bit 2
Disables folding of IT instructions:
In some situations, the processor can start executing the first instruction in an IT block while it
is still executing the IT instruction. This behavior is called IT folding, and improves
performance, However, IT folding can cause jitter in looping. If a task must avoid jitter, set the
DISFOLD bit to 1 before executing the task, to disable IT folding.
Bit 1 DISDEFWBUF
This bit only affects write buffers implemented in the Cortex-M4 processor.
Disables write buffer use during default memory map accesses: This causes all BusFaults to
be precise BusFaults but decreases performance because any store to memory must
complete before the processor can execute the next instruction.
Bit 0 DISMCYCINT
Disables interrupt of multi-cycle instructions. When set to 1, disables interruption of load
multiple and store multiple instructions. This increases the interrupt latency of the processor
because any LDM or STM must complete before the processor can stack the current state and
enter the interrupt handler.
0: Enables IT instructions folding.
1: Disables IT instructions folding.
0: Enable write buffer use
1: Disable write buffer use: Stores to memory is completed before next instruction.
0: Enable interruption latency of the processor (load/store and multiply/divide operations).
1: Disable interruptions latency.
PM0214 Rev 10
Core peripherals
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