Architectures and Processors

Cortex-M3 and PrimeCell uDMAC Bus Arbitration in TI CC2640R2F The integration of the ARM Cortex-M3 microcontroller and the PrimeCell uDMAC (Micro Direct Memory Access Controller) in the Texas Instruments CC2640R2F Bluetooth controller presents a complex scenario where bus arbitration between the two masters can lead to performance bottlenecks. The Cortex-M3 and the uDMAC both operate…

ARM Cortex-A53 Cache Architecture and Physical Address Flush Limitations The ARM Cortex-A53 processor, a widely used 64-bit ARMv8-A core, employs a sophisticated cache architecture designed to optimize performance while maintaining coherency across multiple levels of caching. The Cortex-A53 features separate Level 1 (L1) instruction and data caches, as well as a unified Level 2 (L2)…

FPCA in Cortex-M4: Context and Functionality The Floating-Point Context Active (FPCA) bit is a critical component of the Cortex-M4 processor’s control register, specifically within the CONTROL register. This bit plays a pivotal role in managing the state of the Floating-Point Unit (FPU) and its associated context. The FPCA bit is set to 1 whenever the…

System-Level vs PE-Level Generic Timer Implementation in ARM Cortex-A53 The ARM Cortex-A53 processor, a widely used 64-bit core in the ARMv8-A architecture, incorporates a Generic Timer that is essential for timekeeping, scheduling, and synchronization tasks. However, the implementation and operation of the Generic Timer can be understood at two distinct levels: the System Level and…

ARM Cortex-A53 Generic Timer and System Counter Overview The ARM Cortex-A53 processor, part of the ARMv8-A architecture, incorporates a sophisticated timing mechanism known as the Generic Timer. This timer is crucial for various system operations, including scheduling, synchronization, and timekeeping across multiple cores. The Generic Timer operates in conjunction with the System Counter, a global…

ARM Cortex-R4 Instruction Pre-Fetch Unit (PFU) and Flash Diagnostics Conflict The ARM Cortex-R4 processor, like many modern embedded processors, employs an Instruction Pre-Fetch Unit (PFU) to improve performance by fetching instructions ahead of their execution. This mechanism is critical for maintaining the pipeline’s efficiency, ensuring that the processor has a steady stream of instructions to…

ARM Cortex-A35 ARMv8.0-A Compliance and GICv4.0 Interface The ARM Cortex-A35 is a highly efficient processor core designed for power-sensitive applications, often used in embedded systems, IoT devices, and mobile platforms. A critical aspect of understanding its capabilities lies in its adherence to the ARMv8-A architecture and the specific extensions it supports. The Cortex-A35 is explicitly…

ARMv8-M Secure and Non-Secure Mode Transitions During Interrupt Handling The ARMv8-M architecture introduces a robust security model that partitions the processor into Secure and Non-Secure states. This partitioning is critical for modern embedded systems, where secure and non-secure software components must coexist while maintaining isolation. A common scenario involves a Non-Secure world interrupt handler calling…

ARM Cortex-A53 TLB Population Challenges with EPDx Bits Enabled The ARM Cortex-A53 processor, a widely used 64-bit core in embedded systems, employs a Translation Lookaside Buffer (TLB) to cache virtual-to-physical address translations, significantly reducing memory access latency. However, a nuanced issue arises when the EPDx (Translation Control Register Exception Permission Disable) bits in the TCR_ELx…

ARM Cortex-A53 L1 and L2 Cache Invalidation Across Multiple Cores In a multi-core ARM Cortex-A53 system, cache coherency is a critical aspect of ensuring data consistency across cores, especially when dealing with shared memory regions and DMA (Direct Memory Access) transfers. The primary issue arises when one core, such as Core0, invalidates a specific virtual…