PCI2050B: The PCI Bus devices connected on secondary bus are not detecting.

Hi TI, 

followed the reference schematics and implementation guide but devices connected on the secondary bus not getting detected. 

Can u please help me out with this? 

How to assign idsel to the devices on secondary bus? 

Is there any role of idsel in not getting detected? 

I have assigned 24th bit and 25th bit of secondary bus for each two pci slots. Is this ok or can u suggest any changes. 

Thanks & regards

Venkat. 

Hi Venkat,

Please note that I've requested clarity on the work-around in our previous discussion, as before the system did not hang when PCI cards were connected through the PCI2050B: https://e2e.ti.com/support/interface-group/interface/f/interface-forum/1328799/pci2050b-carrier-board-designed-with-pci2050b-for-pci-bus-slot-extension-leading-to-sbc-fail-or-hanging-issue 

I've also requested your schematics, but have not received them.

Please also note the IDSEL portion of the EVM schematic here:

Best,
David

Hi David,

The SBC hang issue was due to external clock provided to both SBC and PCI Bridge. Rectified with disabling the same.

i Can't share the schematics as it is confidential. But i can explain through flowchart.

SBC--> PCI BRIDGE (33Mhz) (PCI2050B) --> (IDSEL- SAD24)PCI BRIDGE 33MHZ (PCI2050B) -->PMC SLOT1 (IDSEL-SAD24)

                                                                                                                                               --> PMC SLOT2 (IDSEL- SAD25)

The devices connected on second PCI bridge is not getting detected when checked on sbc.

But both the bridges are getting detected.

Hope you have understood. The devices connected with second PCI2050B on secondary BUS are not getting detected.

Regards,

Venkat

Hi Venkat,

Thanks for additional clarifications. Are you stating that you go from SBC <--> PCI2050B <--> PCI2050B <--> 2x PCI slots ?

Have you verified the INTx# routing in your design as well?

Best,
David