Datasheet

Table Of Contents
24
Atmel | SMART SAM D20 [DATASHEET]
Atmel-42129K–SAM-D20_datasheet–06/2014
10. Processor and Architecture
10.1 Cortex-M0+ Processor
The Atmel
®
SAM D20 implements the ARM
®
Cortex
®
-M0+ processor, which is based on the ARMv6 architecture and
Thumb
®
-2 ISA. The Cortex M0+ is 100% instruction set compatible with its predecessor, the Cortex-M0 processor, and
upward compatible with the Cortex-M3 and Cortex-M4 processors. The ARM Cortex-M0+ implemented is revision r0p1.
For more information, refer to www.arm.com.
10.1.1 Cortex-M0+ Configuration
Note: 1. All software run in privileged mode only
The ARM Cortex-M0+ processor has two bus interfaces:
z Single 32-bit AMBA
®
3 AHB-Lite™ system interface that provides connections to peripherals and all system
memory, including flash and RAM
z Single 32-bit I/O port bus interfacing to the PORT with one-cycle loads and stores
10.1.2 Cortex-M0+ Peripherals
z System Control Space (SCS)
z The processor provides debug through registers in the SCS. Refer to the Cortex-M0+ Technical Reference
Manual for details (www.arm.com).
z System Timer (SysTick)
z The System Timer is a 24-bit timer that extends the functionality of both the processor and the NVIC. Refer
to the Cortex-M0+ Technical Reference Manual for details (www.arm.com).
Feature Configurable Option SAM D20 Configuration
Interrupts External interrupts 0-32 32
Data endianness Little-endian or big-endian Little-endian
SysTick timer Present or absent Present
Number of watchpoint comparators 0, 1, 2 2
Number of breakpoint comparators 0, 1, 2, 3, 4 4
Halting debug support Present or absent Present
Multiplier Fast or small Fast (single cycle)
Single-cycle I/O port Present or absent Present
Wake-up interrupt controller Supported or not supported Not supported
Vector Table Offset Register Present or absent Present
Unprivileged/Privileged support Present or absent Absent
Memory Protection Unit Not present or 8-region Not present
Reset all registers Present or absent Absent
(1)
Instruction fetch width 16-bit only or mostly 32-bit 32-bit