Visible to Intel only — GUID: nik1410564871967
Ixiasoft
Visible to Intel only — GUID: nik1410564871967
Ixiasoft
5.9. LMI Signals
LMI interface is used to write log error descriptor information in the TLP header log registers. The LMI access to other registers is intended for debugging, not normal operation.
The LMI interface is synchronized to pld_clk and runs at frequencies up to 250 MHz. The LMI address is the same as the Configuration Space address. The LMI interface provides the same access to Configuration Space registers as Configuration TLP requests. Register bits have the same attributes, (read only, read/write, and so on) for accesses from the LMI interface and from Configuration TLP requests. The 32-bit read and write data is driven, LSB to MSB over 4 consecutive cycles.
When a LMI write has a timing conflict with configuration TLP access, the configuration TLP accesses have higher priority. LMI writes are held and executed when configuration TLP accesses are no longer pending. An acknowledge signal is sent back to the Application Layer when the execution is complete.
All LMI reads are also held and executed when no configuration TLP requests are pending. The LMI interface supports two operations: local read and local write. The timing for these operations complies with the Avalon-MM protocol described in the Avalon Interface Specifications. LMI reads can be issued at any time to obtain the contents of any Configuration Space register. LMI write operations are not recommended for use during normal operation. The Configuration Space registers are written by requests received from the PCI Express link and there may be unintended consequences of conflicting updates from the link and the LMI interface. LMI Write operations are provided for AER header logging, and debugging purposes only.
- In Root Port mode, do not access the Configuration Space using TLPs and the LMI bus simultaneously.
Signal |
Direction |
Description |
---|---|---|
lmi_dout[7:0] | Output |
Data outputs. Data is driven from LSB, [7:0], to MSB,[31:24]. The LSB coincides withlmi_ack. |
lmi_rden | Input |
Read enable input. |
lmi_wren | Input |
Write enable input. |
lmi_ack | Output |
Write execution done/read data valid. |
lmi_addr[11:0] | Input |
Address inputs, [1:0] not used. |
lmi_din[7:0] | Input |
Data inputs. Data is driven from LSB, [7:0], to MSB,[31:24]. The LSB coincides with lim_wren. |