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
73 while (hi < hi_target) {
74 hi = timer_hw->timerawh;
75 tight_loop_contents();
76 }
77 while (hi == hi_target && timer_hw->timerawl < (uint32_t) target) {
78 hi = timer_hw->timerawh;
79 tight_loop_contents();
80 }
81 }
4.7.4.4. Complete example using Pico SDK
Pico Examples: https://github.com/raspberrypi/pico-examples/tree/pre_release/timer/hello_timer/hello_timer.c Lines 11 - 57
11 volatile bool timer_fired = false;
12
13 int64_t alarm_callback(alarm_id_t id, void *user_data) {
14 printf("Timer %d fired!\n", (int) id);
15 timer_fired = true;
16 // Can return a value here in us to fire in the future
17 return 0;
18 }
19
20 bool repeating_timer_callback(struct repeating_timer *t) {
21 printf("Repeat at %lld\n", time_us_64());
22 return true;
23 }
24
25 int main() {
26 setup_default_uart();
27 printf("Hello Timer!\n");
28
29 // Call alarm_callback in 2 seconds
30 add_alarm_in_ms(2000, alarm_callback, NULL, false);
31
32 // Wait for alarm callback to set timer_fired
33 while (!timer_fired) {
34 tight_loop_contents();
35 }
36
37 // Create a repeating timer that calls repeating_timer_callback.
38 // If the delay is > 0 then this is the delay between the previous callback ending and the
Ê next starting.
39 // If the delay is negative (see below) then the next call to the callback will be exactly
Ê 500ms after the
40 // start of the call to the last callback
41 struct repeating_timer timer;
42 add_repeating_timer_ms(500, repeating_timer_callback, NULL, &timer);
43 sleep_ms(3000);
44 bool cancelled = cancel_repeating_timer(&timer);
45 printf("cancelled... %d\n", cancelled);
46 sleep_ms(2000);
47
48 // Negative delay so means we will call repeating_timer_callback, and call it again
49 // 500ms later regardless of how long the callback took to execute
50 add_repeating_timer_ms(-500, repeating_timer_callback, NULL, &timer);
51 sleep_ms(3000);
52 cancelled = cancel_repeating_timer(&timer);
53 printf("cancelled... %d\n", cancelled);
54 sleep_ms(2000);
RP2040 Datasheet
4.7. Timer 562