diff --git a/examples/systick_irq/README.md b/examples/systick_irq/README.md
index 26e561ef98affb57cc7e1b2b8c752c089c86b81e..9ca11cb3c225054e2fe688168274efd48eff9adf 100644
--- a/examples/systick_irq/README.md
+++ b/examples/systick_irq/README.md
@@ -4,11 +4,11 @@ interrupts for timing. Many bare-metal and RTOS based embedded applications will
use the Systick IRQ for timing, periodic housekeeping and task arbitration so
knowing how to set that up is useful.
-Note that this example is *NOT* compatible with the Delay_*() functions that are
-part of the ch32v003fun library - those functions use the Systick counter for
-doing busy-wait delays and assume that the CNT register rolls over at 32-bit
-maximum. Do not use the built-in Delay_Ms() and related functions when using
-Systick for IRQs.
+This code is compatible with the busywait delay functions in the ch32v003fun
+library because it allows the Systick CNT register to keep running over its full
+32-bit range. It does not set the STRE bit in the CTRL register so the counter
+does not reset when the CMP register matches. In order to do this, the CMP register
+is advanced at every IRQ.
Note also the use of the `__attribute__((interrupt))` syntax in declaring the
IRQ handler. Some of the IRQ examples from the WCH HAL library have slightly
diff --git a/examples/systick_irq_millis/Makefile b/examples/systick_irq_millis/Makefile
deleted file mode 100644
index 641fc4cd43b6b16d9107b38143bb71cc0001d478..0000000000000000000000000000000000000000
--- a/examples/systick_irq_millis/Makefile
+++ /dev/null
@@ -1,11 +0,0 @@
-all : flash
-
-TARGET:=systick_irq_millis
-
-CFLAGS+=-DSTDOUT_UART
-
-include ../../ch32v003fun/ch32v003fun.mk
-
-flash : cv_flash
-clean : cv_clean
-
diff --git a/examples/systick_irq_millis/README.md b/examples/systick_irq_millis/README.md
deleted file mode 100644
index f9d469a8e1efcd6bea087d822b0133785116b694..0000000000000000000000000000000000000000
--- a/examples/systick_irq_millis/README.md
+++ /dev/null
@@ -1,35 +0,0 @@
-# Systick IRQ demonstration
-This example shows how to set up the built-in Systick IRQ to generate periodic
-interrupts for timing. Many bare-metal and RTOS based embedded applications will
-use the Systick IRQ for timing, periodic housekeeping and task arbitration so
-knowing how to set that up is useful.
-
-Systick.h now also contains an arduino-like millis() function to return the
-current time.
-The example has been adapted to use this millis() function for a lock-free program.
-Here, you compare the difference of current time and the last time a task was
-executed against a desired interval. If enough time has passed, run the next
-step.
-
-The benefit of this dance is that the CPU doesn't spend 250ms (12,000,000
-cycles!) drooling onto the carpet.
-Other important tasks (reading buttons, DDoSing your grandma) can run until it's time.
-
-Of course a real RTos would be much more powerful.
-
-Note that this example is *NOT* compatible with the Delay_Ms() function that's
-part of the ch32v003fun library - that function uses the Systick counter for
-doing busy-wait delays and will interfere with its use in generating predictable
-IRQs. Do not use the built-in Delay_Ms() and related functions when using Systick
-for IRQs.
-
-Note also the use of the `__attribute__((interrupt))` syntax in declaring the
-IRQ handler. Some of the IRQ examples from the WCH HAL library have slightly
-different syntax to make use of a fast IRQ mode but which is not compatible with
-generic RISC-V GCC so that feature is not used here.
-
-# Use
-Connect LEDs (with proper current limit resistors) to GPIO pins C0, D0, D4 and
-a 3.3V logic level serial terminal to PD5. The LEDs will flash and an incrementing
-count will be printed to the serial port at rates that are controlled by the
-Systick IRQ.
diff --git a/examples/systick_irq_millis/systick.h b/examples/systick_irq_millis/systick.h
deleted file mode 100644
index 1f3700e660fecb4821dfd9528404fc0c36118618..0000000000000000000000000000000000000000
--- a/examples/systick_irq_millis/systick.h
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Single-File-Header for using SysTick with millisecond interrupts
- * 03-25-2023 E. Brombaugh
- */
-
-#ifndef _SYSTICK_H
-#define _SYSTICK_H
-
-#include <stdint.h>
-
-/* some bit definitions for systick regs */
-#define SYSTICK_SR_CNTIF (1<<0)
-#define SYSTICK_CTLR_STE (1<<0)
-#define SYSTICK_CTLR_STIE (1<<1)
-#define SYSTICK_CTLR_STCLK (1<<2)
-#define SYSTICK_CTLR_STRE (1<<3)
-#define SYSTICK_CTLR_SWIE (1<<31)
-
-volatile uint32_t systick_cnt;
-
-/*
- * Start up the SysTick IRQ
- */
-void systick_init(void)
-{
- /* enable the SysTick IRQ */
- NVIC_EnableIRQ(SysTicK_IRQn);
-
- /* Clear any existing IRQ */
- SysTick->SR &= ~SYSTICK_SR_CNTIF;
-
- /* Set the tick interval to 1ms for normal op */
- SysTick->CMP = (SYSTEM_CORE_CLOCK/1000)-1;
-
- /* Start at zero */
- SysTick->CNT = 0;
- systick_cnt = 0;
-
- /* Enable SysTick counter, IRQ, HCLK/1, auto reload */
- SysTick->CTLR = SYSTICK_CTLR_STE | SYSTICK_CTLR_STIE |
- SYSTICK_CTLR_STCLK | SYSTICK_CTLR_STRE;
-}
-
-#if 1
-/*
- * SysTick ISR just counts ticks
- * note - the __attribute__((interrupt)) syntax is crucial!
- */
-void SysTick_Handler(void) __attribute__((interrupt));
-void SysTick_Handler(void)
-{
- /* clear IRQ */
- SysTick->SR &= 0;
-
- /* update counter */
- systick_cnt++;
-}
-#endif
-
-/*
- * Millisecond delay routine
- */
-void systick_delay_ms(uint32_t milliseconds)
-{
- /* compute end time */
- uint32_t etime = systick_cnt + milliseconds;
-
- /* wait for current time == end time */
- while(systick_cnt != etime);
-}
-
-uint32_t millis() {
- return systick_cnt;
-}
-#endif
diff --git a/examples/systick_irq_millis/systick_irq_millis.c b/examples/systick_irq_millis/systick_irq_millis.c
deleted file mode 100644
index b306cf6ff2cdeb3df15c5b6a7c27750dc07171b8..0000000000000000000000000000000000000000
--- a/examples/systick_irq_millis/systick_irq_millis.c
+++ /dev/null
@@ -1,76 +0,0 @@
-/*
- * Example for using SysTick with IRQs
- * 03-25-2023 E. Brombaugh
- */
-
-// Could be defined here, or in the processor defines.
-#define SYSTEM_CORE_CLOCK 48000000
-#define APB_CLOCK SYSTEM_CORE_CLOCK
-
-#include "ch32v003fun.h"
-#include <stdio.h>
-#include "systick.h"
-
-int main()
-{
- uint32_t count = 0;
-
- SystemInit48HSI();
-
- // start serial @ default 115200bps
- SetupUART( UART_BRR );
- printf("\r\r\n\nsystick_irq example\n\r");
-
- printf("SysTick_Handler = 0x%08X\n\r", SysTick_Handler);
-
- // init systick @ 1ms rate
- printf("initializing systick...");
- systick_init();
- printf("done.\n\r");
-
- // Enable GPIOs
- RCC->APB2PCENR |= RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOC;
-
- // GPIO D0 Push-Pull
- GPIOD->CFGLR &= ~(0xf<<(4*0));
- GPIOD->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP)<<(4*0);
-
- // GPIO D4 Push-Pull
- GPIOD->CFGLR &= ~(0xf<<(4*4));
- GPIOD->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP)<<(4*4);
-
- // GPIO C0 Push-Pull
- GPIOC->CFGLR &= ~(0xf<<(4*0));
- GPIOC->CFGLR |= (GPIO_Speed_10MHz | GPIO_CNF_OUT_PP)<<(4*0);
-
- const uint16_t led_i = 250;
- uint32_t led_t_last;
- uint8_t led_progstep = 0;
-
- printf("looping...\n\r");
- while(1)
- {
- if (millis() - led_t_last >= led_i) {
- switch (led_progstep) {
- case 0:
- GPIOD->BSHR = 1 | (1<<4); // Turn on GPIOs
- break;
- case 1:
- GPIOC->BSHR = 1;
- break;
- case 2:
- GPIOD->BSHR = (1<<16) | (1<<(16+4)); // Turn off GPIODs
- break;
- case 3:
- GPIOC->BSHR = (1<<16);
- printf( "Count: %lu\n\r", count++ );
- break;
- }
- led_progstep++;
- led_t_last = millis();
- if (led_progstep > 3) {
- led_progstep = 0;
- }
- }
- }
-}