topic MPC8548 PCI1 Agent Configuration in PowerQUICC Processors

MPC8548 PCI1 Agent Configuration

mepperly — Thu, 01 Jul 2021 18:38:29 GMT

We have an MPC8548 configured (as far as we can tell) as a PCI1 Agent. When we examine the internal registers, the 8548 appears to be correctly configured as an Agent. However, when the PCI Host asserts IDSEL on the slot the 8548 is located, it does not respond... It does not assert DEVSEL or any other PCI signal.

It has been discussed to set the PCI1 arbiter to external, but we do not see how that could be an issue.

Deep dives into our data sheet have not revealed any reason for it to be non-responsive.

Re: MPC8548 PCI1 Agent Configuration

ufedor — Fri, 02 Jul 2021 03:14:04 GMT

You wrote:

> the 8548 appears to be correctly configured as an Agent

Please describe how you've checked this.

Additionally check whether the agent configuration lock has been disabled in the agent initialization code - refer to the MPC8548E PowerQUICC III Integrated Processor Family Reference Manual, 4.4.3.6 CPU Boot Configuration and 16.3.2.19 PCI Bus Function Register (PBFR).

Re: MPC8548 PCI1 Agent Configuration

mepperly — Fri, 02 Jul 2021 12:51:33 GMT

Per the PBFR, we are in agent mode, ACL is set on boot and then cleared. We manually cleared the ACL and it still would not configure

We boot and clear the ACL, but the configuration cycles are not acknowledged by the agent (no DEVSEL when IDSEL goes high)

It appears we should clear the ACL early in our boot

Re: MPC8548 PCI1 Agent Configuration

ufedor — Sat, 03 Jul 2021 10:19:27 GMT

Please provide:

1) the processor connection schematics as searchable PDF for inspection

2) digital scope of the PCI bus activity (better if signals are probed at the processor's pins)

3) how many boards were tested?