12.4.3. Clocks
The PAC bus clock (CLK_PAC_APB) can be enabled and disabled in the Main Clock module. The default
state of CLK_PAC_APB can be found in the related links.
Related Links
on page 141
12.4.4. DMA
Not applicable.
12.4.5. Interrupts
The interrupt request line is connected to the Interrupt Controller. Using the PAC interrupt requires the
Interrupt Controller to be configured first.
Table 12-1. Interrupt Lines
Instances
NVIC Line
PAC
PACERR
Related Links
Nested Vector Interrupt Controller
12.4.6. Events
The events are connected to the Event System, which may need configuration.
Related Links
12.4.7. Debug Operation
When the CPU is halted in debug mode, write protection of all peripherals is disabled and the PAC
continues normal operation.
12.4.8. Register Access Protection
All registers with write-access can be write-protected optionally by the Peripheral Access Controller
(PAC), except the following registers:
•
Write Control (WRCTRL) register
•
AHB Slave Bus Interrupt Flag Status and Clear (INTFLAGAHB) register
•
Peripheral Interrupt Flag Status and Clear n (INTFLAG A/B/C...) registers
Optional write-protection by the Peripheral Access Controller (PAC) is denoted by the "PAC Write-
Protection" property in each individual register description.
PAC write-protection does not apply to accesses through an external debugger.
12.5. Functional Description
12.5.1. Principle of Operation
The Peripheral Access Control module allows the user to set a write protection on peripheral modules
and generate an interrupt in case of a peripheral access violation. The peripheral’s protection can be set,
Atmel SAM L22G / L22J / L22N [DATASHEET]
Atmel-42402E-SAM L22G / L22J / L22N_Datasheet_Complete-07/2016
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