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 12.5. PCIe® Reset

 When a device is operating in CAPI mode, the resets defined by PCIe have the following behaviors:

  • Fundamental Reset (PERST)

     Fundamental reset is triggered when PERST is applied. There are two types of fundamental resets: cold and warm. A cold reset is when power is applied to the device, and a warm reset is when PERST is asserted with power already applied to the device.

     Asserting PERST has the same effect for both cold and warm resets. The device is restored to the power-on state. For devices that have a base PCIe mode (that is, a bi-modal devices), asserting PERST resets the device to the power-on reset state. After being reset, the bi-modal device is operating in PCIe mode.

     Following a fundamental reset, the PSL must be downloaded for all CAIA-compliant devices with a loadable PSL.

  • Hot Reset (in-band)

     Hot reset is triggered by the TS1 and TS2 training ordered set defined by the PCIe protocol specification.

     When a device receives a hot reset, the PCIe configuration space is reset as defined in the PCIe specification. For bi-modal devices, the CAPI Protocol Enable bit in the Vendor-Specific Extended Capability Structure retains the current value (that is, the CAPI Protocol Enable bit is sticky).

     Following a hot reset, the PSL must be downloaded for all CAIA-compliant devices with a loadable PSL.


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