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urishurish
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feat(watchdog): implement Watchdog peripheral
1 parent 4b6d803 commit f0e8791

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2 files changed

+151
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‎src/peripherals/watchdog.ts‎

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import { RP2040 } from '../rp2040.js';
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import { Timer32, Timer32PeriodicAlarm, TimerMode } from '../utils/timer32.js';
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import { BasePeripheral, Peripheral } from './peripheral.js';
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const CTRL = 0x00; // Control register
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const LOAD = 0x04; // Load the watchdog timer.
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const REASON = 0x08; // Logs the reason for the last reset.
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const SCRATCH0 = 0x0c; // Scratch register
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const SCRATCH1 = 0x10; // Scratch register
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const SCRATCH2 = 0x14; // Scratch register
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const SCRATCH3 = 0x18; // Scratch register
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const SCRATCH4 = 0x1c; // Scratch register
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const SCRATCH5 = 0x20; // Scratch register
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const SCRATCH6 = 0x24; // Scratch register
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const SCRATCH7 = 0x28; // Scratch register
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const TICK = 0x2c; // Controls the tick generator
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// CTRL bits:
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const TRIGGER = 1 << 31;
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const ENABLE = 1 << 30;
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const PAUSE_DBG1 = 1 << 26;
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const PAUSE_DBG0 = 1 << 25;
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const PAUSE_JTAG = 1 << 24;
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const TIME_MASK = 0xffffff;
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const TIME_SHIFT = 0;
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// LOAD bits
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const LOAD_MASK = 0xffffff;
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const LOAD_SHIFT = 0;
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// REASON bits:
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const FORCE = 1 << 1;
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const TIMER = 1 << 0;
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// TICK bits:
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const COUNT_MASK = 0x1ff;
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const COUNT_SHIFT = 11;
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const RUNNING = 1 << 10;
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const TICK_ENABLE = 1 << 9;
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const CYCLES_MASK = 0x1ff;
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const CYCLES_SHIFT = 0;
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const TICK_FREQUENCY = 2_000_000; // Actually 1 MHz, but due to errata RP2040-E1, the timer is decremented twice per tick
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export class RPWatchdog extends BasePeripheral implements Peripheral {
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readonly timer;
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readonly alarm;
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readonly scratchData = new Uint32Array(8);
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private enable = false;
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private tickEnable = true;
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private reason = 0;
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private pauseDbg0 = true;
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private pauseDbg1 = true;
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private pauseJtag = true;
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/** Called when the watchdog triggers - override with your own soft reset implementation */
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onWatchdogTrigger = () => {
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this.rp2040.logger.warn(this.name, 'Watchdog triggered, but no reset handler provided');
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};
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// User provided
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constructor(rp2040: RP2040, name: string) {
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super(rp2040, name);
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this.timer = new Timer32(rp2040.clock, TICK_FREQUENCY);
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this.timer.mode = TimerMode.Decrement;
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this.timer.enable = false;
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this.alarm = new Timer32PeriodicAlarm(this.timer, () => {
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this.reason = TIMER;
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this.onWatchdogTrigger?.();
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});
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this.alarm.target = 0;
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this.alarm.enable = false;
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}
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readUint32(offset: number) {
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switch (offset) {
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case CTRL:
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return (
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(this.timer.enable ? ENABLE : 0) |
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(this.pauseDbg0 ? PAUSE_DBG0 : 0) |
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(this.pauseDbg1 ? PAUSE_DBG1 : 0) |
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(this.pauseJtag ? PAUSE_JTAG : 0) |
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((this.timer.counter & TIME_MASK) << TIME_SHIFT)
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);
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case REASON:
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return this.reason;
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case SCRATCH0:
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case SCRATCH1:
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case SCRATCH2:
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case SCRATCH3:
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case SCRATCH4:
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case SCRATCH5:
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case SCRATCH6:
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case SCRATCH7:
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return this.scratchData[(offset - SCRATCH0) >> 2];
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case TICK:
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// TODO COUNT bits
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return this.tickEnable ? RUNNING | TICK_ENABLE : 0;
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}
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return super.readUint32(offset);
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}
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writeUint32(offset: number, value: number) {
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switch (offset) {
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case CTRL:
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if (value & TRIGGER) {
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this.reason = FORCE;
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this.onWatchdogTrigger?.();
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}
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this.enable = !!(value & ENABLE);
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this.timer.enable = this.enable && this.tickEnable;
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this.alarm.enable = this.enable && this.tickEnable;
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this.pauseDbg0 = !!(value & PAUSE_DBG0);
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this.pauseDbg1 = !!(value & PAUSE_DBG1);
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this.pauseJtag = !!(value & PAUSE_JTAG);
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break;
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case LOAD:
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this.timer.set((value >>> LOAD_SHIFT) & LOAD_MASK);
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break;
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case SCRATCH0:
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case SCRATCH1:
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case SCRATCH2:
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case SCRATCH3:
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case SCRATCH4:
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case SCRATCH5:
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case SCRATCH6:
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case SCRATCH7:
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this.scratchData[(offset - SCRATCH0) >> 2] = value;
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break;
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case TICK:
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this.tickEnable = !!(value & TICK_ENABLE);
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this.timer.enable = this.enable && this.tickEnable;
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this.alarm.enable = this.enable && this.tickEnable;
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// TODO - handle CYCLES (tick also affectes timer)
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break;
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default:
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super.writeUint32(offset, value);
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}
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}
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}

‎src/rp2040.ts‎

Lines changed: 3 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -24,8 +24,9 @@ import { RPTBMAN } from './peripherals/tbman.js';
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import { RPTimer } from './peripherals/timer.js';
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import { RPUART } from './peripherals/uart.js';
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import { RPUSBController } from './peripherals/usb.js';
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import { RPWatchdog } from './peripherals/watchdog.js';
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import { RPSIO } from './sio.js';
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import { ConsoleLogger, Logger, LogLevel } from './utils/logging.js';
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import { ConsoleLogger, LogLevel, Logger } from './utils/logging.js';
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export const FLASH_START_ADDRESS = 0x10000000;
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export const RAM_START_ADDRESS = 0x20000000;
@@ -161,7 +162,7 @@ export class RP2040 {
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0x4004c: this.adc,
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0x40050: this.pwm,
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0x40054: new RPTimer(this, 'TIMER_BASE'),
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0x40058: new UnimplementedPeripheral(this, 'WATCHDOG_BASE'),
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0x40058: new RPWatchdog(this, 'WATCHDOG_BASE'),
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0x4005c: new RP2040RTC(this, 'RTC_BASE'),
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0x40060: new UnimplementedPeripheral(this, 'ROSC_BASE'),
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0x40064: new UnimplementedPeripheral(this, 'VREG_AND_CHIP_RESET_BASE'),

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