Registers can be 8, 16, or 32 bits wide. Atomic 8-, 16- and 32-bit accesses are supported. In addition, the 8-bit quarters and 16-bit halves of a 32-bit register, and the 8-bit halves of a 16-bit register can be accessed directly.
Some registers are optionally write-protected by the Peripheral Access Controller (PAC). Optional PAC write-protection is denoted by the "PAC Write-Protection" property in each individual register description. For details, refer to the related links.
On SAM L11 devices, the Mix-Secure peripheral has different types of registers (Non-Secure, Secure, Write-Secure, Mix-Secure, and Write-Mix-Secure) with different access permissions for each bitfield. Refer to Mix-Secure Peripherals for more details. In the following register descriptions, the access permissions are specified as shown in the following figure.