I'm trying to setup a PWM channel on a AM335x evkit, where I have problems when accessing some registers. I already searched the forums, but the answers I found did not help.
I perform the following operations to setup the channel:
HWREG(SOC_PRCM_REGS + CM_PER_EPWMSS0_CLKCTRL) |= CM_PER_EPWMSS0_CLKCTRL_MODULEMODE_ENABLE;
while ((HWREG(SOC_PRCM_REGS + CM_PER_EPWMSS0_CLKCTRL) & CM_PER_EPWMSS0_CLKCTRL_MODULEMODE) != CM_PER_EPWMSS0_CLKCTRL_MODULEMODE_ENABLE) { }
while ((HWREG(SOC_PRCM_REGS + CM_PER_EPWMSS0_CLKCTRL) & CM_PER_EPWMSS0_CLKCTRL_IDLEST) != (CM_PER_EPWMSS0_CLKCTRL_IDLEST_FUNC << CM_PER_EPWMSS0_CLKCTRL_IDLEST_SHIFT)) { }
HWREG(pwmOutConfig.m_pwmSubSystemBaseAddress + PWMSS_CLOCK_CONFIG) = PWMSS_EHRPWM_CLK_EN_ACK;
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBCTL) &= EHRPWM_TBCTL_PHSEN;
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBCTL) |= (EHRPWM_TBCTL_SYNCOSEL_DISABLE << EHRPWM_TBCTL_SYNCOSEL_SHIFT);
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBCTL) &= ~EHRPWM_TBCTL_FREE_SOFT;
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBCTL) &= ~EHRPWM_TBCTL_CTRMODE;
HWREG(SOC_CONTROL_REGS + CONTROL_PWMSS_CTRL) = CONTROL_PWMSS_CTRL_PWMSS0_TBCLKEN;
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBCTL) |= EHRPWM_TBCTL_PRDLD;
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBCTL) &= ~EHRPWM_TBCTL_CLKDIV;
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBCTL) |= (clkDiv << EHRPWM_TBCTL_CLKDIV_SHIFT);
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBCTL) &= ~EHRPWM_TBCTL_HSPCLKDIV;
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBCTL) |= (hspClkDiv << EHRPWM_TBCTL_HSPCLKDIV_SHIFT);
Now I want to set the PWM period:
HWREG(pwmOutConfig.m_pwmModuleBaseAddress + EHRPWM_TBPRD) = periodCountRegValue;
This operation fails (program jumps to Abort/Undef Handler). The access of other registers (like e.g. EPWM0_CMPA) which follow this initialization also fail.
Is there something else I have to initialize the get the above access working?
Thanks
Thomas
