CPU

The ARM® Cortex®-M4 processor has a 32-bit instruction set (Thumb®-2 technology) that implements a superset of 16- and 32-bit instructions to maximize code density and performance.

This processor implements several features that enable energy-efficient arithmetic and high-performance signal processing including:

The ARM Cortex Microcontroller Software Interface Standard (CMSIS) hardware abstraction layer for the ARM Cortex processor series is implemented and available for the M4 CPU.

Real-time execution is highly deterministic in thread mode, to and from sleep modes, and when handling events at configurable priority levels via the nested vectored interrupt controller (NVIC).

Executing code from flash will have a wait state penalty on the nRF52 Series. The section Electrical specification shows CPU performance parameters including wait states in different modes, CPU current and efficiency, and processing power and efficiency based on the CoreMark® benchmark.

The ARM System Timer (SysTick) is present on the device. The SysTick's clock will only tick when the CPU is running or when the system is in debug interface mode.

Electrical specification

CPU performance

The CPU clock speed is 64 MHz. Current and efficiency data is taken when in System ON and the CPU is executing the CoreMark® benchmark. It includes power regulator and clock base currents. All other blocks are IDLE.

Symbol Description Min. Typ. Max. Units
WFLASH

CPU wait states, running from flash

0 2  
WRAM

CPU wait states, running from RAM

0  
CMFLASH

CoreMark1, running from flash

144 CoreMark
CMFLASH/MHz

CoreMark per MHz, running from flash

2.25 CoreMark/MHz
CMFLASH/mA

CoreMark per mA, running from flash, DCDC 3V

65 CoreMark/mA

CPU and support module configuration

The ARM® Cortex®-M4 processor has a number of CPU options and support modules implemented on the device.

Option / Module Description Implemented
Core options
NVIC Nested vector interrupt controller 30 vectors
PRIORITIES Priority bits 3
WIC Wakeup interrupt controller NO
Endianness Memory system endianness Little endian
Bit-banding Bit banded memory NO
DWT Data watchpoint and trace NO
SysTick System tick timer YES
Modules
MPU Memory protection unit YES
FPU Floating-point unit NO
DAP Debug access port YES
ETM Embedded trace macrocell NO
ITM Instrumentation trace macrocell NO
TPIU Trace port interface unit NO
ETB Embedded trace buffer NO
FPB Flash patch and breakpoint unit YES
HTM AMBA® AHB trace macrocell NO
1 Using IAR v6.50.1.4452 with flags --endian=little --cpu=Cortex-M4 -e --fpu=VFPv4_sp –Ohs --no_size_constraints