Datasheet

2.11.5.2. Dormant
The hello_dormant example, https://github.com/raspberrypi/pico-playground/tree/master/sleep/hello_dormant/
hello_dormant.c, demonstrates dormant mode. The example takes the following steps:
•
Run all clocks in the system from XOSC
•
Configure a GPIO interrupt for the "dormant_wake" hardware which can wake both the ROSC and XOSC from
dormant mode
•
Put the XOSC into dormant mode which stops all processor execution (and all other clocked logic on the chip)
immediately
•
When GPIO 10 goes high, the XOSC is started again and execution of the program continues
hello_dormant uses sleep_goto_dormant_until_pin under the hood:
Pico Extras: https://github.com/raspberrypi/pico-extras/tree/master/src/rp2_common/pico_sleep/sleep.c Lines 134 - 155
134 void sleep_goto_dormant_until_pin(uint gpio_pin, bool edge, bool high) {
135 bool low = !high;
136 bool level = !edge;
137
138 // Configure the appropriate IRQ at IO bank 0
139 assert(gpio_pin < NUM_BANK0_GPIOS);
140
141 uint32_t event = 0;
142
143 if (level && low) event = IO_BANK0_DORMANT_WAKE_INTE0_GPIO0_LEVEL_LOW_BITS;
144 if (level && high) event = IO_BANK0_DORMANT_WAKE_INTE0_GPIO0_LEVEL_HIGH_BITS;
145 if (edge && high) event = IO_BANK0_DORMANT_WAKE_INTE0_GPIO0_EDGE_HIGH_BITS;
146 if (edge && low) event = IO_BANK0_DORMANT_WAKE_INTE0_GPIO0_EDGE_LOW_BITS;
147
148 gpio_set_dormant_irq_enabled(gpio_pin, event, true);
149
150 _go_dormant();
151 // Execution stops here until woken up
152
153 // Clear the irq so we can go back to dormant mode again if we want
154 gpio_acknowledge_irq(gpio_pin, event);
155 }
2.12. Chip-Level Reset
2.12.1. Overview
The chip-level reset subsystem resets the whole chip, placing it in a default state. This happens at initial power-on,
during a power supply brown-out event or when the chip’s RUN pin is taken low. The chip can also be reset via the
Rescue Debug Port. See Section 2.3.4.2, “Rescue DP” for details.
The subsystem has two reset outputs. rst_n_psm, which resets the whole chip, except the debug port, and rst_n_dp, which
only resets the Rescue DP. Both resets are held low at initial power-on, during a brown-out event or when RUN is low.
rst_n_psm can additionally be held low by the Rescue DP via the subsystem’s psm_restart input. This allows the chip to be
reset via the Rescue DP without resetting the Rescue DP itself. The subsystem releases chip level reset by taking
rst_n_psm high, handing control to the Power-on State Machine, which continues to start up the chip. See Section 2.13,
“Power-On State Machine” for details.
The chip level reset subsystem is shown in Figure 21, and more information is available in the following sections.
RP2040 Datasheet
2.12. Chip-Level Reset 190