mirror of
https://github.com/mytechnotalent/Embedded-Hacking.git
synced 2026-05-24 00:14:04 +02:00
Kevin Thomas
65 lines
1.8 KiB
C
65 lines
1.8 KiB
C
/**
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* @file rp2350_delay.c
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* @brief Delay driver implementation for RP2350.
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* @author Kevin Thomas
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* @date 2026
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*
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* Busy-wait millisecond and microsecond delays calibrated for
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* a 12 MHz clock.
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*
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* MIT License
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*
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* Copyright (c) 2026 Kevin Thomas
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in all
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* copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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* SOFTWARE.
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*/
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#include "rp2350_delay.h"
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void delay_ms(uint32_t ms)
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{
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if (ms == 0)
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return;
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__asm__ volatile (
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"mov r4, #3600\n\t"
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"mul r5, %0, r4\n\t"
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"1:\n\t"
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"subs r5, #1\n\t"
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"bne 1b\n\t"
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:
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: "r" (ms)
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: "r4", "r5", "cc"
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);
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}
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void delay_us(uint32_t us)
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{
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if (us == 0)
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return;
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__asm__ volatile (
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"mov r4, #4\n\t"
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"mul r5, %0, r4\n\t"
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"1:\n\t"
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"subs r5, #1\n\t"
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"bne 1b\n\t"
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:
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: "r" (us)
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: "r4", "r5", "cc"
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);
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}
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