topic K22: Example for LPUART that can work in VLPS mode in Kinetis Microcontrollers

K22: Example for LPUART that can work in VLPS mode

guest253456 — Fri, 18 Mar 2022 12:48:23 GMT

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?

Re: K22: Example for LPUART that can work in VLPS mode

bobpaddock — Mon, 21 Mar 2022 14:07:52 GMT

OSC_SetExtRefClkConfig(OSC0, &oscerConfig);

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

Re: K22: Example for LPUART that can work in VLPS mode

guest253456 — Tue, 22 Mar 2022 04:34:43 GMT

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

This is enough?

Re: K22: Example for LPUART that can work in VLPS mode

guest253456 — Tue, 22 Mar 2022 12:36:19 GMT

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)

Re: K22: Example for LPUART that can work in VLPS mode

mjbcswitzerland — Tue, 22 Mar 2022 14:35:09 GMT

Hi

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

Regards

Mark