PCI bus is not used in MPC8378

[rajeshanarasimh]

Hi,

I am using MPC8378 processor in legacy design. MPC8378 PCI bus is not used in the design and all PCI Address lines were kept open in the design. We have initialized the RCWHR[PCIHOST] = 1 & RCWHR[PCIARB] = 1 in software. We haven't initialized the PCIACR[PM] = 1 or PCI_GCR[BBR] = 1 in software. Now we don't have opportunity to update the software. Is there any impact if we keep default value to PCIACR[PM] & PCI_GCR[BBR] in software?

Thanks for your support.

Regards,

Rajesh

Honeywell-Bangalore

[r8070z]

Have a great day,

PCIACR[PM] = 1 or PCI_GCR[BBR] set the PCI bus parked with the PCI controller when the MPC8378 drives PCI_AD[31:0] pins as outputs. So impact is that you may have float 32 inputs. These input signals are ignored if the PCI control inputs are terminated properly i.e. are in inactive state. However these floats inputs may increase power consumption and noise.

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[rajeshanarasimh]

Thanks for the reply. As per below e-mail, PCI pins will have noise. Are you suspecting emission or susceptible noise issue if we float these pins? Any failure reported due to these floating pins?

Thanks,

Rajesh

Honeywell-Bangalore