From 51637a2ee4548384a3fb559c9c1b69c7798be639 Mon Sep 17 00:00:00 2001
From: recallmenot <edmund.raile@proton.me>
Date: Sun, 4 Jun 2023 06:58:51 +0200
Subject: [PATCH] ch32v003fun.c and .h added interrupt suspension functions
---
ch32v003fun/ch32v003fun.c | 45 +++++++++++++++++++++++++++++++++++++++
ch32v003fun/ch32v003fun.h | 5 +++++
2 files changed, 50 insertions(+)
diff --git a/ch32v003fun/ch32v003fun.c b/ch32v003fun/ch32v003fun.c
index 3db230e..671f081 100644
--- a/ch32v003fun/ch32v003fun.c
+++ b/ch32v003fun/ch32v003fun.c
@@ -765,6 +765,51 @@ void InterruptVectorDefault()
.option pop;\n");
}
+
+
+/*
+SUSPEND ALL INTERRUPTS EXCEPT
+The following 3 functions serve to suspend all interrupts, except for the one you momentarily need.
+The purpose of this is to not disturb the one interrupt of interest and let it run unimpeded.
+procedure:
+1. save the enabled IRQs: uint32_t IRQ_backup = NVIC_get_enabled_IRQs();
+2. disable all IRQs: NVIC_clear_all_IRQs_except(IRQ_of_interest);
+3. restore the previously enabled IRQs: NVIC_restore_IRQs(IRQ_backup);
+
+bit layout of the IRQ backup
+bit 0 | 1 | 2 | 3 | 4 | 5 | 6 .. 22 | 23 .. 28
+IRQn 2 | 3 | 12 | res | 14 | res | 16 .. 31 | 32 .. 38
+IRQn 2 and 3 aren't actually user-settable (see RM).
+
+Specifying an invalid IRQn_to_keep like 0 will disable all interrupts.
+*/
+
+RV_STATIC_INLINE uint32_t NVIC_get_enabled_IRQs()
+{
+ return ( ((NVIC->ISR[0] >> 2) & 0b11) | ((NVIC->ISR[0] >> 12) << 2) | ((NVIC->ISR[1] & 0b1111111) << 23) );
+}
+
+RV_STATIC_INLINE void NVIC_clear_all_IRQs_except(uint8_t IRQn_to_keep)
+{
+ if (!(IRQn_to_keep >> 5)) { // IRQn_to_keep < 32
+ NVIC->IRER[0] = (~0) & (~(1 << IRQn_to_keep));
+ NVIC->IRER[1] = (~0);
+ }
+ else {
+ IRQn_to_keep = IRQn_to_keep >> 5;
+ NVIC->IRER[0] = (~0);
+ NVIC->IRER[1] = (~0) & (~(1 << IRQn_to_keep));
+ }
+}
+
+RV_STATIC_INLINE void NVIC_restore_IRQs(uint32_t old_state)
+{
+ NVIC->IENR[0] = (old_state >> 2) << 12;
+ NVIC->IENR[1] = old_state >> 23;
+}
+
+
+
void handle_reset()
{
asm volatile( "\n\
diff --git a/ch32v003fun/ch32v003fun.h b/ch32v003fun/ch32v003fun.h
index 10d5fc2..cc62930 100644
--- a/ch32v003fun/ch32v003fun.h
+++ b/ch32v003fun/ch32v003fun.h
@@ -5024,6 +5024,11 @@ void SystemInit24HSI( void ); // No PLL, just raw internal RC oscillator.
void SystemInitHSE( int HSEBYP );
void SystemInitHSEPLL( int HSEBYP );
+// SUSPEND ALL INTERRUPTS EXCEPT
+RV_STATIC_INLINE uint32_t NVIC_get_enabled_IRQs();
+RV_STATIC_INLINE void NVIC_clear_all_IRQs_except(uint8_t IRQn_to_keep);
+RV_STATIC_INLINE void NVIC_restore_IRQs(uint32_t old_state);
+
#define UART_BAUD_RATE 115200
#define OVER8DIV 4
#define INTEGER_DIVIDER (((25 * (APB_CLOCK)) / ((OVER8DIV) * (UART_BAUD_RATE))))
--
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