Secure World Variable Allocation in ARM TrustZone-M When working with ARM TrustZone-M on Cortex-M processors, one of the critical tasks is ensuring that sensitive data, such as cryptographic keys or secure application state, is stored in memory that is only accessible to the Secure World. This is particularly important for maintaining the integrity and confidentiality…
ARM Cortex-M33/M35P Bit Banding Absence in ARMv8-M Architecture The ARM Cortex-M33 and Cortex-M35P processors, based on the ARMv8-M architecture, do not support the bit-banding memory model, a feature that was available in earlier ARM Cortex-M processors such as the Cortex-M3 and Cortex-M4. Bit banding allows individual bits in memory to be directly accessed and modified…
GPIO Functionality in CMSIS-Driver and Standard Naming Conventions The ARM Cortex-M microcontrollers are widely used in embedded systems due to their efficiency, scalability, and robust ecosystem. One of the key components of this ecosystem is the Cortex Microcontroller Software Interface Standard (CMSIS), which provides a standardized hardware abstraction layer for Cortex-M processors. However, a common…
Cortex-M7 SPI Peripheral Register Base Address Confusion The Cortex-M7 is a high-performance microcontroller core designed by ARM, widely used in embedded systems for its advanced features such as a dual-issue pipeline, floating-point unit, and cache memory. However, one common source of confusion among developers working with Cortex-M7-based microcontrollers, such as the NXP i.MX RT1060 used…
ARM Cortex-M33 IMPRECISERR Default Implementation and Documentation Ambiguity The ARM Cortex-M33 processor, a member of the ARMv8-M architecture, introduces several advanced features, including enhanced fault handling mechanisms. One such mechanism is the IMPRECISERR fault, which is part of the Configurable Fault Status Register (CFSR) within the System Control Block (SCB). The IMPRECISERR fault is specifically…
ARM Cortex-M3 Interrupt Latency During AHB Memory Access The ARM Cortex-M3 processor is widely used in embedded systems due to its balance of performance, power efficiency, and real-time capabilities. One of the critical aspects of real-time systems is interrupt latency, which is the time between the occurrence of an interrupt and the start of the…
Cortex-M0+ Hard Fault Triggered by DSB Instruction at FFFF FFFEh The Cortex-M0+ processor is a popular choice for embedded systems due to its simplicity, low power consumption, and cost-effectiveness. However, its reduced instruction set and lack of certain features compared to higher-end Cortex-M processors can lead to subtle issues, especially when porting software like FreeRTOS….
ARM Cortex-M7 Runtime Error Handling Requirements The ARM Cortex-M7 processor, like other Cortex-M series processors, is designed for embedded systems where reliability and real-time performance are critical. Runtime error handling in such systems must be efficient, deterministic, and minimally intrusive to the real-time operation of the system. The Cortex-M7 architecture provides several mechanisms for handling…
ARM Cortex-A7 Secure World Interrupt Handling in Trusty When working with the ARM Cortex-A7 processor in a secure world environment such as Trusty, one of the critical challenges is ensuring that interrupts are correctly configured and received. The Cortex-A7, being part of the ARMv7-A architecture, supports both secure and non-secure states, and the handling of…
Cortex-R52 Data Cache Access and Debugging Challenges The Cortex-R52 processor, part of ARM’s real-time processor family, is designed for safety-critical and high-performance embedded systems. One of the key features of the Cortex-R52 is its data cache, which significantly improves performance by reducing memory access latency. However, accessing or reading the contents of the data cache…