T4241 processor RESET_REQ_B signal probe output looks like continous pulses

[kumar_086]

Dear Experts,

We are bringing up a T4241 processor board, loaded with RCW file in NOR Flash. In other boards we are able to see U-Boot booting.

In a particular board when we power on the board with UART, there is continuous character '≡' (triple bar) is printing on the terminal.

When we probed the processor signals its observed that signal 'RESET_REQ_B' output looks like a pulsed signal.

I'm new to this platform and requesting your help to resolve this.

Thanks

[kumar_086]

Thanks r8070z. After reprogramming Uboot image once again in NOR Flash, it's working now.

Regards!

[r8070z · Accepted solution]

It is supposed that RESET_REQ signal triggers circuit which assigns PORESET (or HRESET). On reset RESET_REQ is negated and device tried to start. So we can imagine that toggling RESET_REQ signal means that during start due to some error device assigns RESET_REQ and as result is trying to start again and again. Possible reasons for RESET_REQ_B assertion you can find in the section “Reset Request Status Register (DCFG_CCSR_RSTRQSR1)” of the QorIQ T4240 Reference Manual. Probably Uboot image in the NOR flash has been damaged and device executes something wrong.