Contents
What are the three design categories of ARM processors?
ARM processors offer a variety of capabilities for different purposes. Depending on the level of performance you need, you can choose between the Cortex-A, Cortex-R, or Cortex-M categories of high-level processors.
What is ARM assembly code?
ARM is a RISC (Reduced instruction set Computing) processor and therefore has a simplified instruction set (100 instructions or less) and more general purpose registers than CISC. In ARM, most instructions can be used for conditional execution. The Intel x86 and x86-64 series of processors use the little-endian format.
How is JTAG implemented in ARM core devices?
This article will teach you about the intersection between JTAG and Arm core devices, with special attention paid to the Arm Debug Interface or ADI. Thus far in our series on JTAG, we’ve looked at the IEEE 1149.1 standard, including the test access port (TAP) controller and the TAP state machine.
What does JTAG stand for in microcontrollers?
JTAG stands for Joint Test Action Group (the group who defined the JTAG standard) and was designed as a way to test boards. JTAG allows the user to talk to the bits and pieces of the microcontroller. In many cases, this involves giving them a set of instructions or programming the board. The JTAG standard defines 5 pins:
Which is an example of a JTAG-DP interface?
While the JTAG-DP is a common and familiar example of a debugging interface, most relevant to our discussion is the JTAG alternative defined for Arm devices, the Arm Serial Wire Debug (SWD). SWD was developed as a two-wire interface for Arm-core devices with limited pin counts.
Is the JTAG interface included in the Adi?
The ADI forms the base for debugging operations with Arm-core processors, and part of this standard includes a JTAG interface as well as the Serial Wire Debug (SWD) alternative. The topic of this article is the ADI, and particularly the hardware interface layers.