K22: Example for LPUART that can work in VLPS mode

[guest253456]

I'm trying to get LPUART to work while CPU is in VLPS mode. I'm using the following code

        CLOCK_EnableClock(kCLOCK_PortD);
        PORT_SetPinMux(PORTD, 2U, kPORT_MuxAlt6);
        PORT_SetPinMux(PORTD, 3U, kPORT_MuxAlt6);
        CLOCK_SetLpuartClock(2U);

        oscer_config_t oscerConfig;
        oscerConfig.enableMode = kOSC_ErClkEnable | kOSC_ErClkEnableInStop;
        oscerConfig.erclkDiv = 0;

        OSC_SetExtRefClkConfig(OSC0, &oscerConfig);

        lpuart_config_t config;
        LPUART_GetDefaultConfig(&config);
        config.baudRate_Bps = 115200;
        config.enableTx = true;
        config.enableRx = true;

        LPUART_Init(LPUART0, &config, CLOCK_GetFreq(kCLOCK_Osc0ErClk));
        LPUART_EnableInterrupts(LPUART0, kLPUART_RxDataRegFullInterruptEnable);
        EnableIRQ(LPUART0_IRQn);

This only works while by debugger is connected and CPU is prevented from going to stop mode. If i enter stop mode, its not getting interrupts anymore. Are there any code examples that i can refer to?

[mjbcswitzerland]

Hi

See https://community.nxp.com/message/421247#421247

Regards

Mark

[guest253456]

>

oscer_config_t oscerConfig;
oscerConfig.enableMode = kOSC_ErClkEnable | kOSC_ErClkEnableInStop;
oscerConfig.erclkDiv = 0;

This is enough?

[bobpaddock]

OSC_SetExtRefClkConfig(OSC0, &oscerConfig);

Is the external Osc configured to work in the low power mode?

[guest253456]

Which all power modes can the LPUART work? I was trying with VLPS which does not work, nor with Stop mode with "kSMC_PartialStop". It only works with "kSMC_PartialStop1" but by then the power consumption is very high(20mW vs <4mW)