FRDM-KL05z: after exit from VLLS3, execution starts with Reset_Handler as expected but execution fails when reaching main()

mjoa — Fri, 19 Dec 2014 23:00:11 GMT

Hi,

When running low_power_demo from official package KL05-SC.zip as well as FRDM-KL05Z Quick Start Package to test deep sleep/wakeup on FRDM_KL05z, I found this scenario.

From the following trace, after exit from VLLS3, execution starts with Reset_Handler (the instruction pointed to by the RESET vector address) as expected but execution fails when reaching main():

-------------------------------------------------------------------------------------------------

Enter the key number to choose one mode: 9LLWU PE1 = 0x00, LLWU PE2 = 0x00

LLWU ME = 0x01, LLWU F1 = 0x00

LLWU F3 = 0x00

LLWU FILT1 = 0x00, LLWU FILT2 = 0x00

enter into VLLS3 mode--.

[outSRS]Wakeup bit set from low power mode exit

[outSRS]SMC_PMPROT = 0x02

[outSRS]SMC_PMCTRL = 0x04

[outSRS]SMC_STOPCTRL = 0x03

[outSRS]SMC_PMSTAT = 0x01

[outSRS] VLLS3 exit

K05

Unrecognized Kinetis package code. SRAM Size: 4 KB

Silicon rev 15

Flash size: 32 KB program flash, 1 KB protection region

[LLWU ISR]

[LLWU ISR] ****WUF3_MWUF0 IF LPT0 *****

-------------------------------------------------------------------------------------------------

MCU just stuck there until Reset button is explicitly pressed. I would expect main() to be re-executed when running the Reset_Handler:

Reset_Handler PROC

EXPORT Reset_Handler [WEAK]

IMPORT SystemInit

IMPORT __main

LDR R0, =SystemInit

BLX R0

LDR R0, =__main

BX R0

ENDP

Is there anything that is needed in order to have reset flow run properly and have main() reexecute?

Thanks for your help.

Re: FRDM-KL05z: after exit from VLLS3, execution starts with Reset_Handler as expected but execution fails when reaching main()

mjoa — Mon, 22 Dec 2014 17:04:53 GMT

By referring the code in KL25_SC, I have modified llwu_isr() as follows (pls check the tag CHANGE for my hack):

if (LLWU_F3 & LLWU_F3_MWUF0_MASK) {

printf("\n [LLWU ISR] ****WUF3_MWUF0 IF LPT0 *****\r\n");

SIM_SCGC5 |= SIM_SCGC5_LPTMR_MASK; //CHANGE:

LPTMR0_CSR |= LPTMR_CSR_TCF_MASK; // write 1 to TCF to clear the LPT timer compare flag

// LPTMR0_CSR = ( LPTMR_CSR_TEN_MASK | LPTMR_CSR_TIE_MASK | LPTMR_CSR_TCF_MASK );

// LLWU_F3 |= LLWU_F3_MWUF0_MASK; //CHANGE by comment out: write one to clear the flag

It now seems to work now where main() could be re-executed after waking up from VLLS3.

topic Re: FRDM-KL05z: after exit from VLLS3, execution starts with Reset_Handler as expected but execution fails when reaching main() in Kinetis Microcontrollers

FRDM-KL05z: after exit from VLLS3, execution starts with Reset_Handler as expected but execution fails when reaching main()

Re: FRDM-KL05z: after exit from VLLS3, execution starts with Reset_Handler as expected but execution fails when reaching main()