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+
- 2.4.1. Features
- 2.4.2. Functional Description
- 2.4.3. Programmer’s model
- 2.4.4. System control
- 2.4.5. NVIC
- 2.4.6. MPU
- 2.4.7. Debug
- 2.4.8. List of Registers
- 2.5. Memory
- 2.6. Boot Sequence
- 2.7. Bootrom
- 2.7.1. Bootrom Source
- 2.7.2. Processor Controlled Boot Sequence
- 2.7.3. Bootrom Contents
- 2.7.4. USB Mass Storage Interface
- 2.7.5. USB PICOBOOT Interface
- 2.8. Power Supplies
- 2.9. On-Chip Voltage Regulator
- 2.10. Power Control
- 2.11. Chip-Level Reset
- 2.12. Power-On State Machine
- 2.13. Subsystem Resets
- 2.14. Clocks
- 2.14.1. Overview
- 2.14.2. Clock sources
- 2.14.2.1. Ring Oscillator
- 2.14.2.1.1. Mitigating ROSC frequency variation due to process
- 2.14.2.1.2. Mitigating ROSC frequency variation due to voltage
- 2.14.2.1.3. Mitigating ROSC frequency variation due to temperature
- 2.14.2.1.4. Automatic mitigation of ROSC frequency variation due to PVT
- 2.14.2.1.5. Automatic overclocking using the ROSC
- 2.14.2.2. Crystal Oscillator
- 2.14.2.3. External Clocks
- 2.14.2.4. Relaxation Oscillators
- 2.14.2.5. PLLs
- 2.14.2.1. Ring Oscillator
- 2.14.3. Clock Generators
- 2.14.4. Frequency Counter
- 2.14.5. Resus
- 2.14.6. Programmer’s Model
- 2.14.7. List of registers
- 2.15. Crystal Oscillator (XOSC)
- 2.16. Ring Oscillator (ROSC)
- 2.17. PLL
- 2.18. GPIO
- 2.19. Sysinfo
- 2.20. Syscfg
- Chapter 3. PIO
- Chapter 4. Peripherals
- 4.1. USB
- 4.2. DMA
- 4.3. UART
- 4.4. I2C
- 4.4.1. Features
- 4.4.2. IP Configuration
- 4.4.3. I2C Overview
- 4.4.4. I2C Terminology
- 4.4.5. I2C Behaviour
- 4.4.6. I2C Protocols
- 4.4.7. Tx FIFO Management and START, STOP and RESTART Generation
- 4.4.8. Multiple Master Arbitration
- 4.4.9. Clock Synchronization
- 4.4.10. Operation Modes
- 4.4.11. Spike Suppression
- 4.4.12. Fast Mode Plus Operation
- 4.4.13. Bus Clear Feature
- 4.4.14. IC_CLK Frequency Configuration
- 4.4.15. DMA Controller Interface
- 4.4.16. List of Registers
- 4.5. SPI
- 4.5.1. Overview
- 4.5.2. Functional Description
- 4.5.3. Operation
- 4.5.3.1. Interface reset
- 4.5.3.2. Configuring the SSP
- 4.5.3.3. Enable PrimeCell SSP operation
- 4.5.3.4. Clock ratios
- 4.5.3.5. Programming the SSPCR0 Control Register
- 4.5.3.6. Programming the SSPCR1 Control Register
- 4.5.3.7. Frame format
- 4.5.3.8. Texas Instruments synchronous serial frame format
- 4.5.3.9. Motorola SPI frame format
- 4.5.3.10. Motorola SPI Format with SPO=0, SPH=0
- 4.5.3.11. Motorola SPI Format with SPO=0, SPH=1
- 4.5.3.12. Motorola SPI Format with SPO=1, SPH=0
- 4.5.3.13. Motorola SPI Format with SPO=1, SPH=1
- 4.5.3.14. National Semiconductor Microwire frame format
- 4.5.3.15. Examples of master and slave configurations
- 4.5.3.16. PrimeCell DMA interface
- 4.5.4. List of Registers
- 4.6. PWM
- 4.7. Timer
- 4.8. Watchdog
- 4.9. RTC
- 4.10. ADC and Temperature Sensor
- 4.11. SSI
- 4.11.1. Overview
- 4.11.2. Features
- 4.11.3. IP Modifications
- 4.11.4. Clock Ratios
- 4.11.5. Transmit and Receive FIFO Buffers
- 4.11.6. 32-Bit Frame Size Support
- 4.11.7. SSI Interrupts
- 4.11.8. Transfer Modes
- 4.11.9. Operation Modes
- 4.11.10. Partner Connection Interfaces
- 4.11.11. DMA Controller Interface
- 4.11.12. APB Interface
- 4.11.13. List of Registers
- Chapter 5. Electrical and Mechanical
- Appendix A: Register Field Types
- Appendix B: Errata
INTF Register
Description
Interrupt Force
Table 571. INTF
Register
Bits Name Description Type Reset
31:4 Reserved. - - -
3 ALARM_3 RW 0x0
2 ALARM_2 RW 0x0
1 ALARM_1 RW 0x0
0 ALARM_0 RW 0x0
INTS Register
Description
Interrupt status after masking & forcing
Table 572. INTS
Register
Bits Name Description Type Reset
31:4 Reserved. - - -
3 ALARM_3 RO 0x0
2 ALARM_2 RO 0x0
1 ALARM_1 RO 0x0
0 ALARM_0 RO 0x0
4.8. Watchdog
4.8.1. Overview
The watchdog is a countdown timer that can restart parts of the chip if it reaches zero. This can be used to restart the
processor if software gets stuck in an infinite loop. The programmer must periodically write a value to the watchdog to
stop it from reaching zero.
The watchdog is reset by rst_n_run, which is deasserted as soon as the digital core supply (DVDD) is powered and stable,
and the RUN pin is high. This allows the watchdog reset to feed into the power-on state machine (see Power-On State
Machine) and reset controller (see Subsystem Resets), resetting their dependants if they are selected in the WDSEL register.
The WDSEL register exists in both the power-on state machine and reset controller.
4.8.2. Tick generation
The watchdog reference clock, clk_tick, is driven from clk_ref. Ideally clk_ref will be configured to use the Crystal
Oscillator so that it provides an accurate reference clock. The reference clock is divided internally to generate a tick
(nominally 1μs) to use as the watchdog tick. The tick is configured using the TICK register.
RP2040 Datasheet
4.8. Watchdog 567