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I'm using the Keil uVision IDE tool and the LPC2129. My question is about setting up single edge hardware PWMs. Someone previously posted the following code: REG(PWM0_PR)=0x0000; //no prescaler - one cpu clk is one PWM clk REG(PWM0_MCR)=0x0002; //Reset timer counter register on match0 REG(PWM0_PCR)=0x7E00; //enable each individual PWM, single edge REG(PWM0_TCR)=0x000A; //Reset TC counter REG(PWM0_MR0)=0x0400; //set up the PWM period REG(PWM0_LER)|=BIT0; //Latch the value REG(PWM0_MR1)=0x0050; //set up initial PWM duty cycle REG(PWM0_LER)|=BIT1; //latch the value REG(PWM0_MR2)=0x0100; //set up initial PWM duty cycle REG(PWM0_LER)|=BIT2; //latch the value REG(PWM0_MR3)=0x150; //set up initial PWM duty cycle REG(PWM0_LER)|=BIT3; //latch the value REG(PWM0_TCR)=0x0009; //set the TC coutner and enable all PWMs I added "PINSEL0 = 0x0005800A;" to enable UART1 and PWM 1-3, however I'm unsure of what else is required to have an output of the initial PWM duty cycle. Thanks. |
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LPC2129 PWM
Started by ●July 10, 2004
Reply by ●July 11, 20042004-07-11
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Frequency: > 1 kHz Resolution: 16 bit Channels: 3 My code generates three 16 bit values (0-65535) that are directly proportional to 0-100% duty cycle. The following is what I have thus far: PINSEL0 = 0x0005800A; //Enable UART1 RxD1/TxD1 & PWM 1, 2, 3 PWMPR = 0x0000; //no prescaler - one cpu clk is one PWM clk PWMMCR = 0x0002; //Reset timer counter register on match0 PWMPCR = 0x7E00; //enable each individual PWM, single edge PWMTCR = 0x000A; //Reset TC counter PWMMR0 = 0x0400; //set up the PWM period I'm unsure of how to change PWMPR or PWMMR0 to manipulate the frequency and period respectively. In addition, does PWMMR1 need to be equated to the 16 bit value in hex in order to set the duty cycle? Thanks. |
