Arria V Avalon-ST Interface for PCIe Solutions User Guide
4.12. Power Management Signals
|   Signal  |  
        Direction  |  
        Description  |  
     
|---|---|---|
| pme_to_cr |   Input  |  
        Power management turn off control register. Root Port—When this signal is asserted, the Root Port sends the PME_turn_off message. Endpoint—This signal is asserted to acknowledge the PME_turn_off message by sending pme_to_ack to the Root Port.  |  
     
| pme_to_sr |   Output  |  
        Power management turn off status register. Root Port—This signal is asserted for 1 clock cycle when the Root Port receives the pme_turn_off acknowledge message. Endpoint—This signal is asserted for 1 cycle when the Endpoint receives the PME_turn_off message from the Root Port.  |  
     
| pm_event |   Input  |  
        Power Management Event. This signal is only available for Endpoints. The Endpoint initiates a a power_management_event message (PM_PME) that is sent to the Root Port. If the Hard IP is in a low power state, the link exits from the low-power state to send the message. This signal is positive edge-sensitive.  |  
     
| pm_event_func[2:0] |   Input  |  
      Specifies the function associated with a Power Management Event. | 
| pm_data[9:0] |   Input  |  
        Power Management Data. This bus indicates power consumption of the component. This bus can only be implemented if all three bits of AUX_power (part of the Power Management Capabilities structure) are set to 0. This bus includes the following bits: 
 For example, the two registers might have the following values: 
 To find the maximum power consumed by this component, multiply the data value by the data Scale (114 × .01 = 1.14). 1.14 watts is the maximum power allocated to this component in the power state selected by the data_select field.  |  
     
| pm_auxpwr |   Input  |  
        Power Management Auxiliary Power: This signal can be tied to 0 because the L2 power state is not supported.  |  
     
|   Bits  |  
        Field  |  
        Description  |  
     
|---|---|---|
|   [31:24]  |  
      Data register |   This field indicates in which power states a function can assert the PME# message.  |  
     
|   [23:16]  |  
      reserved |   —  |  
     
|   [15]  |  
      PME_status |   When set to 1, indicates that the function would normally assert the PME# message independently of the state of the PME_en bit.  |  
     
|   [14:13]  |  
      data_scale |   This field indicates the scaling factor when interpreting the value retrieved from the data register. This field is read-only.  |  
     
|   [12:9]  |  
      data_select |   This field indicates which data should be reported through the data register and the data_scale field.  |  
     
|   [8]  |  
      PME_EN |   1: indicates that the function can assert PME#0: indicates that the function cannot assert PME#  |  
     
|   [7:2]  |  
      reserved |   —  |  
     
|   [1:0]  |  
      PM_state |   Specifies the power management state of the operating condition being described. The following encodings are defined: 
 A device returns 2b’11 in this field and Aux or PME Aux in the type register to specify the D3-Cold PM state. An encoding of 2b’11 along with any other type register value specifies the D3-Hot state.  |