P4080 HRESET Problem

[ali_erceylan]

Two images that I attach below show PORESET and HRESET signals. In the first image, microprocessor works properly. But, microprocessor sometimes does not work and we obtain a measurement like the second picture from the oscilloscope. Why does not hreset go high?

[ufedor]

It is required to check the following points:

1) power sequencing (P4080/P4081 QorIQ Integrated Processor Hardware Specifications, 2.2 Power sequencing)

2) TRST_B is pulsed asserted during POR (P4080/P4081 QorIQ Integrated Processor Hardware Specifications, Figure 56. Legacy JTAG Interface Connection)

3) PLL voltage supply filters are implemented as described in the P4080/P4081 QorIQ Integrated Processor Hardware Specifications, 3.3.1 PLL Power Supply Filtering

4) termination of all signals having explicit notes in the P4080/P4081 QorIQ Integrated Processor Hardware Specifications, Table 1. Pins List by Bus and use a digital scope to check POR levels of all there signals.