ST STM32F4 Series Programming Manual page 253

PM0214
Bit 31 ASPEN: Enables CONTROL<2> setting on execution of a floating-point instruction. This
results in automatic hardware state preservation and restoration, for floating-point context, on
exception entry and exit.
0: Disable CONTROL<2> setting on execution of a floating-point instruction.
1: Enable CONTROL<2> setting on execution of a floating-point instruction.
Bit 30 LSPEN:
0: Disable automatic lazy state preservation for floating-point context.
1: Enable automatic lazy state preservation for floating-point context.
Bits 29:9 Reserved.
Bit 8 MONRDY:
0: DebugMonitor is disabled or priority did not permit setting MON_PEND when the floating-
point stack frame was allocated.
1: DebugMonitor is enabled and priority permits setting MON_PEND when the floating-point
stack frame was allocated.
Bit 7 Reserved.
Bit 6 BFRDY:
0: BusFault is disabled or priority did not permit setting the BusFault handler to the pending
state when the floating-point stack frame was allocated.
1: BusFault is enabled and priority permitted setting the BusFault handler to the pending state
when the floating-point stack frame was allocated.
Bit 5 MMRDY:
0: MemManage is disabled or priority did not permit setting the MemManage handler to the
pending state when the floating-point stack frame was allocated.
1: MemManage is enabled and priority permitted setting the MemManage handler to the
pending state when the floating-point stack frame was allocated.
Bit 4 HFRDY:
0: Priority did not permit setting the HardFault handler to the pending state when the floating-
point stack frame was allocated.
1: Priority permitted setting the HardFault handler to the pending state when the floating-point
stack frame was allocated.
Bit 3 THREAD:
0: Mode was not Thread Mode when the floating-point stack frame was allocated.
1: Mode was Thread Mode when the floating-point stack frame was allocated.
Bit 2 Reserved.
Bit 1 USER:
0: Privilege level was not user when the floating-point stack frame was allocated.
1: Privilege level was user when the floating-point stack frame was allocated.
Bit 1 LSPACT:
0: Lazy state preservation is not active.
1: Lazy state preservation is active. floating-point stack frame is allocated but saving state to it
is deferred.
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Core peripherals
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