The Chip don't Reset when pin PORz go LOW in Linux!

YanChang Liang

Other Parts Discussed in Thread: TPS3707, TPS65217

The Chip don't Reset when pin PORz go LOW in Linux!
my PCB AM335x ZCZ PORz signal is driver by power supervisor chip TPS3707-33D,
when i push the MR_n pin of TPS3707-33D to GND, RESET_n pin of TPS3707-33D got an 200mS Low Pluse.
if this happen in U-boot running, the chip will reset,u-boot restart,this is ok;
but if this happen in Linux running, the chip just HALT,u-boot don't restart! what's wrong?

any guys can test this on BeagleBone or BBB,force PMIC_PGOOD signal low when running linux?

see what happen next.

over 11 years ago

0 Biser Gatchev-XID over 11 years ago

TI__Guru**** 393215 points

Generally PORz should be used only for cold reset, when the processor is initially powered up. For resetting the processor during normal operation WARMRESETn pin should be used.

0 Biser Gatchev-XID over 11 years ago in reply to Biser Gatchev-XID

TI__Guru**** 393215 points

Another possible problem will be the state of the SYSBOOT pins when you apply PORz when the kernel is operating. You should check their levels while PORz is low.

0 YanChang Liang over 11 years ago in reply to Biser Gatchev-XID

Prodigy 70 points

SYSBOOT has 100k pull-up /pulldown resistor,and there are used as lcd_data[0-15],which are output from CPU. TPS3707-33D VDD is 3.3v,when 3.3v power down,it should reset CPU.

0 YanChang Liang over 11 years ago in reply to YanChang Liang

Prodigy 70 points

No PMIC in my design,TPS3707 give power on reset to CPU,and sine 3.3v power down, it should reset CPU !

0 YanChang Liang over 11 years ago in reply to Biser Gatchev-XID

Prodigy 70 points

1.I‘ve just check SYSBOOT,the SYSBOOT[5] = 1,after PORz go high,CLKOUT1 has 24MHZ clock output,i think CPU has latched these pins.but what make cpu halt?

TPS3707 MR -------------------\___/------------------------------------------------------------

TPS3707 RESET_n ------------\_________200ms______/-----------------------------------------------

CPU CLKOUT1 ---------------------------------------------------XXXXXXXXXXXXXXXXXXXXXXXX

2.any guys can test this on BeagleBone or BBB,force PMIC_PGOOD signal low when running linux?

0 Biser Gatchev-XID over 11 years ago in reply to YanChang Liang

TI__Guru**** 393215 points

YanChang Liang said:
any guys can test this on BeagleBone or BBB,force PMIC_PGOOD signal low when running linux?

PMIC_PGOOD is a push-pull output from the BeagleBone PMIC, it must never be forced low or the TPS65217 will be damaged.

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The Chip don't Reset when pin PORz go LOW in Linux!