24.5 Peripheral Dependencies
| Peripheral
Name |
Base Address | NVIC IRQ Index: Source | MCLK AHBx/APBx Clock Enable Mask Bit |
PAC Peripheral Identifier
(PAC.WRCTRL.PERIDx) |
EVSYS Users
(EVSYS.USERm) |
EVSYS Generator
(EVSYS.CHANNELn.EVGENx) |
DMA Trigger Index:Source (DMAC.CHCTRLBk.TRIGx) |
Power Domain |
|---|---|---|---|---|---|---|---|---|
| RTC | 0X4401_8000 | 12 : PER_0, PER_1, PER_2, PER_3, PER_4, PER_5, PER_6, PER_7, CMP_0, CMP_1, CMP_2, CMP_3, TAMPER, OVF | MCLK.CLKMSK1[12] | 12 | 1 : TAMPER | 6-13 : Periodic Interval n (RTC_PERn),
n=0,1…7 14 : Daily Period (RTC_PERD) 15-18 : Compare n (RTC_CMPn), n=0,1,2,3 19 : Tamper 20 : Overflow (OVF) |
4 : RTC Timestamp (TIMESTAMP) |
VDDCORE_BU |
Clocks
The RTC bus clock (CLK_RTC_APB) can be enabled and disabled in the Main Clock module MCLK, and the default state of CLK_RTC_APB can be found in Peripheral Clock Masking section.
A 32KHz or 1KHz oscillator clock (CLK_RTC_OSC) is required to clock the RTC. This clock must be configured and enabled in the 32KHz oscillator controller (OSC32KCTRL) before using the RTC.
This oscillator clock is asynchronous to the bus clock (CLK_RTC_APB). Due to this asynchronicity, writing to certain registers will require synchronization between the clock domains. Refer to Synchronization for further details.
Debug Operation
When the CPU is halted in debug mode the RTC will halt normal operation. The RTC can be forced to continue operation during debugging. Refer to DBGCTRL for details.
Register Access Protection
All registers with write-access are optionally write-protected by the peripheral access controller (PAC), except the following registers:
- Interrupt Flag Status and Clear (INTFLAG) register
Write-protection is denoted by the "PAC Write-Protection" property in the register description.
Write-protection does not apply to accesses through an external debugger. Refer to the PAC - Peripheral Access Controller for details.
Analog Connections
A 32.768kHz crystal can be connected to the XIN32 and XOUT32 pins, along with any required load capacitors. See the Electrical Characteristics for details on recommended crystal characteristics and load capacitors.