Flash Memory Access Latency on ARM Cortex-M4 The ARM Cortex-M4 processor, like many embedded microcontrollers, relies heavily on flash memory for storing program code and constants. However, accessing flash memory is inherently slower than accessing SRAM due to the physical characteristics of flash technology. The Cortex-M4 core itself does not dictate the exact number of…
ARM Cortex-M7 Lockstep Configuration and Functional Safety Requirements The ARM Cortex-M7 processor is a high-performance embedded processor designed for real-time applications, particularly in automotive and industrial sectors where functional safety is paramount. One of the key features that enable functional safety in these environments is the dual-core lockstep configuration. The lockstep mechanism involves running two…
Cortex-M0 Interrupt Handler Fails to Return to Reset Handler The issue at hand involves a Cortex-M0 processor that enters an interrupt handler for a timer but fails to return to the reset handler after completing the interrupt service routine (ISR). The processor executes the timer handler correctly for the first interrupt but then gets stuck,…
STM32F407VG UART Transmission Issue with Arduino Uno as Receiver The core issue revolves around the STM32F407VG microcontroller failing to transmit the character ‘A’ via UART to an Arduino Uno, which is configured as the receiver. The STM32F407VG is programmed to send the character ‘A’ continuously in an infinite loop, but the Arduino Uno does not…
LPC546xx SWD Lockout Due to Enhanced Code Read Protection (eCRP) The LPC546xx microcontroller family, based on the ARM Cortex-M4 core, features Enhanced Code Read Protection (eCRP) as a security mechanism to prevent unauthorized access to the device’s flash memory. When eCRP is enabled, the Serial Wire Debug (SWD) interface is typically locked, rendering standard debugging…
ARM Cortex-M33 SAU and PPC Configuration for Non-Secure UART1 Access The ARM Musca-A1 platform, based on the ARM Cortex-M33 processor, implements a TrustZone security architecture that divides the system into Secure and Non-Secure worlds. Configuring peripherals like UART1 for Non-Secure access requires careful manipulation of the Security Attribution Unit (SAU) and the Peripheral Protection Controller…
Cortex-A72 Memory Benchmark Performance Degradation and Gradual Improvement The observed behavior in the Cortex-A72 memory benchmark, where performance gradually improves over multiple runs, is a complex interplay between the processor’s cache hierarchy, DRAM behavior, and the memory access patterns of the benchmark itself. The benchmark involves a 400MB buffer with pseudo-random memory accesses, which inherently…
ARM Cortex-A72 64-bit MADD Throughput Limitations The ARM Cortex-A72, a high-performance processor core within the ARMv8-A architecture, exhibits a significant performance discrepancy when executing 64-bit integer multiply-accumulate (MADD) instructions compared to 32-bit integer, single-precision (float), and double-precision (double) operations. Specifically, the throughput of 64-bit MADD instructions is approximately one-third that of the other data types….
ARM Cortex-A72 AArch32 Virtual-to-Physical Address Translation Challenges The ARM Cortex-A72 processor, when operating in AArch32 mode, presents a unique set of challenges when attempting to translate virtual addresses to physical addresses, particularly in user space. The Cortex-A72, part of ARM’s Cortex-A series, is a high-performance processor that supports both AArch32 and AArch64 execution states. In…
AXI Protocol Handshake Rules and Deadlock Scenarios in Multi-Transaction Sequences The AXI protocol defines strict rules for handshaking between the master and slave using the xREADY and xVALID signals to ensure data integrity and avoid deadlocks. A deadlock occurs when two or more transactions are waiting for each other to complete, resulting in a system…