S32R274 reset_B keeps low

[wangzhebuaa]

Hi all,

       I am debugging my board based on S32R274 now, but I can encountered a problem: my PE micro USB mulitlink can not connect my device. 

       After checking the JTAG interface signals, I found that the the signal on S32R274 RESET_B pin always keep in LOW after I power on the system(either with or without the JTAG interface connected). And actually, the pin is pull-up to V3.3 by a 4.7K resistor.

       An in S32R274 reference manual Table4-1, it is described that the RESET_B is kept in LOW during POR and RESET stages. It means that my S32R274 is kept in POR/RESET stage, and there is some problem with my S32R274?

      Is there anybody can tell me how can I get throught the problem? Thanks 

[petervlna]

Hello,

Yes, the reset_b is kept low during reset phase. (reset signal is negated)

User cannot easily recognize which reset phase the device actually is and it is not important.

If the device works correctly it will leave reset after phase 3 with any issues.

The question is what you were doing with micro?

What do you see on reset line after power on reset (POR)? Do you see signal toggles before it stays in permanent reset or do you see direct permanent reset after POR.

regards,

Peter

[wangzhebuaa]

How can I know which reset stage it stay in?