Control (CPAC)
register. The below example code sequence enables the FPU in both privileged
and user modes.
; CPACR is located at address 0xE000ED88
LDR.W R0, =0xE000ED88
; Read CPACR
LDR R1, [R0]
; Set bits 20-23 to enable CP10 and CP11 coprocessors
ORR R1, R1, #(0xF << 20)
; Write back the modified value to the CPACR
STR R1, [R0]; wait for store to complete
DSB
;reset pipeline now the FPU is enabled
ISB
3.2
Register Map
Table 3-8 on page 146 lists the Cortex-M4 Peripheral SysTick, NVIC, MPU, FPU and SCB registers.
The offset listed is a hexadecimal increment to the register's address, relative to the Core Peripherals
base address of 0xE000.E000.
Note:
Register spaces that are not used are reserved for future or internal use. Software should
not modify any reserved memory address.
Table 3-8. Peripherals Register Map
See
page
Description
Reset
Type
Name
Offset
System Timer (SysTick) Registers
SysTick Control and Status Register
0x0000.0000
RW
STCTRL
0x010
SysTick Reload Value Register
-
RW
STRELOAD
0x014
SysTick Current Value Register
-
RWC
STCURRENT
0x018
Nested Vectored Interrupt Controller (NVIC) Registers
Interrupt 0-31 Set Enable
0x0000.0000
RW
EN0
0x100
Interrupt 32-63 Set Enable
0x0000.0000
RW
EN1
0x104
Interrupt 64-95 Set Enable
0x0000.0000
RW
EN2
0x108
Interrupt 96-113 Set Enable
0x0000.0000
RW
EN3
0x10C
Interrupt 0-31 Clear Enable
0x0000.0000
RW
DIS0
0x180
Interrupt 32-63 Clear Enable
0x0000.0000
RW
DIS1
0x184
Interrupt 64-95 Clear Enable
0x0000.0000
RW
DIS2
0x188
Interrupt 96-113 Clear Enable
0x0000.0000
RW
DIS3
0x18C
Interrupt 0-31 Set Pending
0x0000.0000
RW
PEND0
0x200
Interrupt 32-63 Set Pending
0x0000.0000
RW
PEND1
0x204
Interrupt 64-95 Set Pending
0x0000.0000
RW
PEND2
0x208
Interrupt 96-113 Set Pending
0x0000.0000
RW
PEND3
0x20C
June 18, 2014
146
Texas Instruments-Production Data
Cortex-M4 Peripherals