Added example demonstrating use of TIM1 for 2 channel PWM output

examples/tim1_pwm/Makefile

+TARGET:=tim1_pwm
+
+all : flash
+
+PREFIX:=riscv64-unknown-elf
+
+GPIO_Toggle:=EXAM/GPIO/GPIO_Toggle/User
+
+CH32V003FUN:=../../ch32v003fun
+MINICHLINK:=../../minichlink
+
+CFLAGS:= \
+	-g -Os -flto -ffunction-sections \
+	-static-libgcc -lgcc \
+	-march=rv32ec \
+	-mabi=ilp32e \
+	-I/usr/include/newlib \
+	-I$(CH32V003FUN) \
+	-nostdlib \
+	-I. -DSTDOUT_UART -Wall
+
+LDFLAGS:=-T $(CH32V003FUN)/ch32v003fun.ld -Wl,--gc-sections
+
+SYSTEM_C:=$(CH32V003FUN)/ch32v003fun.c
+
+$(TARGET).elf : $(SYSTEM_C) $(TARGET).c
+	$(PREFIX)-gcc -o $@ $^ $(CFLAGS) $(LDFLAGS)
+
+$(TARGET).bin : $(TARGET).elf
+	$(PREFIX)-size $^
+	$(PREFIX)-objdump -S $^ > $(TARGET).lst
+	$(PREFIX)-objdump -t $^ > $(TARGET).map
+	$(PREFIX)-objcopy -O binary $< $(TARGET).bin
+	$(PREFIX)-objcopy -O ihex $< $(TARGET).hex
+
+flash : $(TARGET).bin
+	$(MINICHLINK)/minichlink -w $< flash -b
+
+clean :
+	rm -rf $(TARGET).elf $(TARGET).bin $(TARGET).hex $(TARGET).lst $(TARGET).map $(TARGET).hex
+

examples/tim1_pwm/t1pwm.h

+/*
+ * Single-File-Header for using Advanced Control Timer (TIM1) for PWM generation
+ * 03-28-2023 E. Brombaugh
+ */
+
+#ifndef _T1PWM_H
+#define _T1PWM_H
+
+#include <stdint.h>
+
+/*
+ * initialize act
+ */
+void t1pwm_init( void )
+{
+	// Enable GPIOC, GPIOD and TIM1
+	RCC->APB2PCENR |= 	RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOC |
+						RCC_APB2Periph_TIM1;
+	
+	// PD0 is T1CH1N, 50MHz Output PP CNF = 10: Mux PP, MODE = 11: Out 50MHz
+	GPIOD->CFGLR &= ~(GPIO_CFGLR_MODE0 | GPIO_CFGLR_CNF0);
+	GPIOD->CFGLR |= GPIO_CFGLR_CNF0_1 | GPIO_CFGLR_MODE0_0 | GPIO_CFGLR_MODE0_1;
+	
+	// PC4 is T1CH4, 50MHz Output PP CNF = 10: Mux PP, MODE = 11: Out 50MHz
+	GPIOC->CFGLR &= ~(GPIO_CFGLR_MODE4 | GPIO_CFGLR_CNF4);
+	GPIOC->CFGLR |= GPIO_CFGLR_CNF4_1 | GPIO_CFGLR_MODE4_0 | GPIO_CFGLR_MODE4_1;
+		
+	// Reset TIM1 to init all regs
+	RCC->APB2PRSTR |= RCC_APB2Periph_TIM1;
+	RCC->APB2PRSTR &= ~RCC_APB2Periph_TIM1;
+	
+	// CTLR1: default is up, events generated, edge align
+	// SMCFGR: default clk input is CK_INT
+	
+	// Prescaler 
+	TIM1->PSC = 0x0000;
+	
+	// Auto Reload - sets period
+	TIM1->ATRLR = 255;
+	
+	// Reload immediately
+	TIM1->SWEVGR |= TIM_UG;
+	
+	// Enable CH1N output, positive pol
+	TIM1->CCER |= TIM_CC1NE | TIM_CC1NP;
+	
+	// Enable CH4 output, positive pol
+	TIM1->CCER |= TIM_CC4E | TIM_CC4P;
+	
+	// CH1 Mode is output, PWM1 (CC1S = 00, OC1M = 110)
+	TIM1->CHCTLR1 |= TIM_OC1M_2 | TIM_OC1M_1;
+	
+	// CH2 Mode is output, PWM1 (CC1S = 00, OC1M = 110)
+	TIM1->CHCTLR2 |= TIM_OC4M_2 | TIM_OC4M_1;
+	
+	// Set the Capture Compare Register value to 50% initially
+	TIM1->CH1CVR = 128;
+	TIM1->CH4CVR = 128;
+	
+	// Enable TIM1 outputs
+	TIM1->BDTR |= TIM_MOE;
+	
+	// Enable TIM1
+	TIM1->CTLR1 |= TIM_CEN;
+}
+
+/*
+ * set timer channel PW
+ */
+void t1pwm_setpw(uint8_t chl, uint16_t width)
+{
+	switch(chl&3)
+	{
+		case 0: TIM1->CH1CVR = width; break;
+		case 1: TIM1->CH2CVR = width; break;
+		case 2: TIM1->CH3CVR = width; break;
+		case 3: TIM1->CH4CVR = width; break;
+	}
+}
+
+/*
+ * force output
+ */
+void t1pwm_force(uint8_t chl, uint8_t val)
+{
+	uint16_t temp;
+	
+	chl &= 3;
+	
+	if(chl < 2)
+	{
+		temp = TIM1->CHCTLR1;
+		temp &= ~(TIM_OC1M<<(8*chl));
+		temp |= (TIM_OC1M_2 | (val?TIM_OC1M_0:0))<<(8*chl);
+		TIM1->CHCTLR1 = temp;
+	}
+	else
+	{
+		chl &= 1;
+		temp = TIM1->CHCTLR2;
+		temp &= ~(TIM_OC1M<<(8*chl));
+		temp |= (TIM_OC1M_2 | (val?TIM_OC1M_0:0))<<(8*chl);
+		TIM1->CHCTLR2 = temp;
+	}
+}
+
+#endif

examples/tim1_pwm/tim1_pwm.c

+/*
+ * Example for using Advanced Control Timer (TIM1) for PWM generation
+ * 03-28-2023 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 "t1pwm.h"
+
+int main()
+{
+	uint32_t count = 0;
+	
+	SystemInit48HSI();
+
+	// start serial @ default 115200bps
+	SetupUART( UART_BRR );
+	Delay_Ms( 100 );
+	printf("\r\r\n\ntim1_pwm example\n\r");
+
+	// init TIM1 for PWM
+	printf("initializing tim1...");
+	t1pwm_init();
+	printf("done.\n\r");
+		
+	printf("looping...\n\r");
+	while(1)
+	{
+		t1pwm_setpw(0, count); // Chl 1
+		t1pwm_setpw(3, (count + 128)&255);	// Chl 4
+		count++;
+		count &= 255;
+		Delay_Ms( 5 );
+	}
+}