Datasheet
Table Of Contents
- RP2040 Datasheet
- Colophon
- Chapter 1. Introduction
- Chapter 2. System Description
- 2.1. Bus Fabric
- 2.2. Address Map
- 2.3. Processor subsystem
- 2.4. Cortex-M0+
- 2.5. DMA
- 2.6. Memory
- 2.7. Boot Sequence
- 2.8. Bootrom
- 2.9. Power Supplies
- 2.10. Core Supply Regulator
- 2.11. Power Control
- 2.12. Chip-Level Reset
- 2.13. Power-On State Machine
- 2.14. Subsystem Resets
- 2.15. Clocks
- 2.16. Crystal Oscillator (XOSC)
- 2.17. Ring Oscillator (ROSC)
- 2.18. PLL
- 2.19. GPIO
- 2.20. Sysinfo
- 2.21. Syscfg
- 2.22. TBMAN
- Chapter 3. PIO
- Chapter 4. Peripherals
- 4.1. USB
- 4.2. UART
- 4.3. I2C
- 4.3.1. Features
- 4.3.2. IP Configuration
- 4.3.3. I2C Overview
- 4.3.4. I2C Terminology
- 4.3.5. I2C Behaviour
- 4.3.6. I2C Protocols
- 4.3.7. Tx FIFO Management and START, STOP and RESTART Generation
- 4.3.8. Multiple Master Arbitration
- 4.3.9. Clock Synchronization
- 4.3.10. Operation Modes
- 4.3.11. Spike Suppression
- 4.3.12. Fast Mode Plus Operation
- 4.3.13. Bus Clear Feature
- 4.3.14. IC_CLK Frequency Configuration
- 4.3.15. DMA Controller Interface
- 4.3.16. Operation of Interrupt Registers
- 4.3.17. List of Registers
- 4.4. SPI
- 4.5. PWM
- 4.6. Timer
- 4.7. Watchdog
- 4.8. RTC
- 4.9. ADC and Temperature Sensor
- 4.10. SSI
- 4.10.1. Overview
- 4.10.2. Features
- 4.10.3. IP Modifications
- 4.10.4. Clock Ratios
- 4.10.5. Transmit and Receive FIFO Buffers
- 4.10.6. 32-Bit Frame Size Support
- 4.10.7. SSI Interrupts
- 4.10.8. Transfer Modes
- 4.10.9. Operation Modes
- 4.10.10. Partner Connection Interfaces
- 4.10.11. DMA Controller Interface
- 4.10.12. APB Interface
- 4.10.13. List of Registers
- Chapter 5. Electrical and Mechanical
- Appendix A: Register Field Types
- Appendix B: Errata
- Appendix C: Documentation Release History
Offset: 0x68
Description
Indicates which SRC is currently selected by the glitchless mux (one-hot).
Table 244.
CLK_ADC_SELECTED
Register
Bits Description Type Reset
31:0 This slice does not have a glitchless mux (only the AUX_SRC field is present,
not SRC) so this register is hardwired to 0x1.
RO 0x00000001
CLOCKS: CLK_RTC_CTRL Register
Offset: 0x6c
Description
Clock control, can be changed on-the-fly (except for auxsrc)
Table 245.
CLK_RTC_CTRL
Register
Bits Name Description Type Reset
31:21 Reserved. - - -
20 NUDGE An edge on this signal shifts the phase of the output by 1
cycle of the input clock
This can be done at any time
RW 0x0
19:18 Reserved. - - -
17:16 PHASE This delays the enable signal by up to 3 cycles of the input
clock
This must be set before the clock is enabled to have any
effect
RW 0x0
15:12 Reserved. - - -
11 ENABLE Starts and stops the clock generator cleanly RW 0x0
10 KILL Asynchronously kills the clock generator RW 0x0
9:8 Reserved. - - -
7:5 AUXSRC Selects the auxiliary clock source, will glitch when
switching
0x0 → clksrc_pll_usb
0x1 → clksrc_pll_sys
0x2 → rosc_clksrc_ph
0x3 → xosc_clksrc
0x4 → clksrc_gpin0
0x5 → clksrc_gpin1
RW 0x0
4:0 Reserved. - - -
CLOCKS: CLK_RTC_DIV Register
Offset: 0x70
Description
Clock divisor, can be changed on-the-fly
RP2040 Datasheet
2.15. Clocks 230