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
Table 280. PHASE
Register
Bits Name Description Type Reset
31:12 Reserved. - - -
11:4 PASSWD set to 0xaa
any other value enables the output with shift=0
RW 0x00
3 ENABLE enable the phase-shifted output
this can be changed on-the-fly
RW 0x1
2 FLIP invert the phase-shifted output
this is ignored when div=1
RW 0x0
1:0 SHIFT phase shift the phase-shifted output by SHIFT input clocks
this can be changed on-the-fly
must be set to 0 before setting div=1
RW 0x0
ROSC: STATUS Register
Offset: 0x18
Description
Ring Oscillator Status
Table 281. STATUS
Register
Bits Name Description Type Reset
31 STABLE Oscillator is running and stable RO 0x0
30:25 Reserved. - - -
24 BADWRITE An invalid value has been written to CTRL_ENABLE or
CTRL_FREQ_RANGE or FREQA or FREQB or DIV or PHASE
or DORMANT
WC 0x0
23:17 Reserved. - - -
16 DIV_RUNNING post-divider is running
this resets to 0 but transitions to 1 during chip startup
RO -
15:13 Reserved. - - -
12 ENABLED Oscillator is enabled but not necessarily running and
stable
this resets to 0 but transitions to 1 during chip startup
RO -
11:0 Reserved. - - -
ROSC: RANDOMBIT Register
Offset: 0x1c
Table 282.
RANDOMBIT Register
Bits Description Type Reset
31:1 Reserved. - -
0 This just reads the state of the oscillator output so randomness is
compromised if the ring oscillator is stopped or run at a harmonic of the bus
frequency
RO 0x1
ROSC: COUNT Register
Offset: 0x20
RP2040 Datasheet
2.17. Ring Oscillator (ROSC) 250