Functional Peripherals Registers
94
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Cortex-M4F Peripherals
2.4.1.1
FPCCR Register (Offset = F34h) [reset = C0000000h]
FPCCR is shown in
and described in
.
Floating Point Context Control Register. The Floating Point Context Control Register (FPCCR) holds
control data for the floating-point unit. Accessible only by privileged software.
Figure 2-4. FPCCR Register
31
30
29
28
27
26
25
24
ASPEN
LSPEN
RESERVED
R/W-1h
R/W-1h
R/W-0h
23
22
21
20
19
18
17
16
RESERVED
R/W-0h
15
14
13
12
11
10
9
8
RESERVED
MONRDY
R/W-0h
R/W-0h
7
6
5
4
3
2
1
0
RESERVED
BFRDY
MMRDY
HFRDY
THREAD
RESERVED
USER
LSPACT
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
R/W-0h
Table 2-8. FPCCR Register Field Descriptions
Bit
Field
Type
Reset
Description
31
ASPEN
R/W
1h
Automatic State Preservation Enable. When this bit is set, it causes
bit [2] of the Special CONTROL register to be set (FPCA) on
execution of a floating point instruction, which results in the floating
point state automatically being preserved on exception entry.
30
LSPEN
R/W
1h
Lazy State Preservation Enable. When the processor performs a
context save, space on the stack is reserved for the floating point
state, but it is not stacked until the new context performs a floating
point operation.
29-9
RESERVED
R/W
0h
8
MONRDY
R/W
0h
Indicates whether the the software executing when the processor
allocated the FP stack frame was able to set the DebugMonitor
exception to pending.
7
RESERVED
R/W
0h
6
BFRDY
R/W
0h
Indicates whether the software executing when the processor
allocated the FP stack frame was able to set the BusFault exception
to pending.
5
MMRDY
R/W
0h
Indicates whether the software executing when the processor
allocated the FP stack frame was able to set the MemManage
exception to pending.
4
HFRDY
R/W
0h
Indicates whether the software executing when the processor
allocated the FP stack frame was able to set the HardFault
exception to pending.
3
THREAD
R/W
0h
Indicates the processor mode was Thread when it allocated the FP
stack frame.
2
RESERVED
R/W
0h
1
USER
R/W
0h
Indicates the privilege level of the software executing was User
(Unpriviledged) when the processor allocated the FP stack frame.
0
LSPACT
R/W
0h
Indicates whether Lazy preservation of the FP state is active.