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 175. Fast Bit
Counting /
Manipulation
Functions.
CODE Cycles Avg
V1
Cycles Avg
V2
Description
'P','3' 18 20 uint32_t _popcount32(uint32_t value)
Return a count of the number of 1 bits in value.
'R','3' 21 22 uint32_t _reverse32(uint32_t value)
Return the bits of value in the reverse order.
'L','3' 13 9.6 uint32_t _clz32(uint32_t value)
Return the number of consecutive high order 0 bits of value. If value is zero, returns
32.
'T','3' 12 11 uint32_t _ctz32(uint32_t value)
Return the number of consecutive low order 0 bits of value. If value is zero, returns
32.
2.8.2.1.2. Fast Bulk Memory Fill / Copy Functions
These are highly optimized bulk memory fill and copy functions commonly provided by most language runtimes.
In general you do not need to call these methods directly as the SDK pico_mem_ops library replaces the corresponding
standard ARM EABI functions by default so that the standard C library functions e.g. memcpy or memset use the Bootrom
implementations automatically (see pico_mem_ops for more details).
Table 176. Optimized
Bulk Memory Fill /
Copy Functions
CODE Description
'M','S' uint8_t *_memset(uint8_t *ptr, uint8_t c, uint32_t n)
Sets n bytes start at ptr to the value c and returns ptr.
'M','4' uint32_t *_memset4(uint32_t *ptr, uint8_t c, uint32_t n)
Sets n bytes start at ptr to the value c and returns ptr. Note this is a slightly more efficient variant of
_memset that may only be used if ptr is word aligned.
'M','C' uint8_t *_memcpy(uint8_t *dest, uint8_t *src, uint32_t n)
Copies n bytes starting at src to dest and returns dest. The results are undefined if the regions overlap.
'C','4' uint8_t *_memcpy44(uint32_t *dest, uint32_t *src, uint32_t n)
Copies n bytes starting at src to dest and returns dest. The results are undefined if the regions overlap.
Note this is a slightly more efficient variant of _memcpy that may only be used if dest and src are word
aligned.
2.8.2.1.3. Flash Access Functions
These are low level flash helper functions.
Table 177. Flash
Access Functions
CODE Description
'I','F' void _connect_internal_flash(void)
Restore all QSPI pad controls to their default state, and connect the SSI to the QSPI pads
RP2040 Datasheet
2.8. Bootrom 161