Posted memory write verification
View Patent ↗A method for verifying the proper communication of data packets from an initiator device on a PCIe data bus to a target device on the data bus. A target-specific counter on the initiator is synchronized to an initiator-specific counter on the target with the same value. The initiator writes the value of the target-specific counter into the tag field of the packet header, and also writes an identifier of the initiator into the header. Then the initiator sends the packet to the target on the PCIe data bus. Upon receipt of the packet, the target reads the identifier and checks the value against the appropriate initiator-specific counter on the target. When the value is not equal to the initiator-specific counter on the target, then it generates an error message. An additional memory write with specific data is posted from the initiator to the target. A memory read is posted of the additional memory write location from the initiator to the target. The operation of the initiator is continued when a good status and data matching the additional write data is returned from the target, and operation is halted when an error status is returned or data that does not match the additional write data.
1. A method of verifying proper communication of data packets from one of a plurality of initiator devices on a data bus to one of a plurality of target devices on the data bus, the method comprising the steps of:
synchronizing a target-specific counter selected from a plurality of target-specific counters on the initiator device where one each of the plurality of target-specific counters is associated with one each of the plurality of target devices on the data bus, and an initiator-specific counter selected from a plurality of initiator-specific counters on the target device, where one each of the plurality of initiator-specific counters is associated with one each of the plurality of initiator devices on the data bus, with a common counter value,
with the initiator device, writing the counter value of the target-specific counter on the initiator device into a header for the packet,
sending the packet from the initiator device to the target device on the data bus,
upon receipt of the packet by the target device, checking the counter value written into the header of the packet with the initiator-specific counter on the target device, and
when the counter value written into the header of the packet is not equal to the initiator-specific counter on the target device, then generating an error message with the target device.
2. The method of claim 1 , wherein the communication bus is a PCIe bus.
3. The method of claim 1 , wherein the communication bus is a PCI-X bus.
4. The method of claim 1 , wherein the initiator device writes the counter value into a tag field of the header of the packet.
5. The method of claim 1 , wherein the initiator device further indicates to the target device which initiator-specific counter the target device should check the counter value written into the header of the packet against, by writing an identifier of the initiator device into the packet header.
6. The method of claim 1 , further comprising the steps of:
Posting an additional memory write with specific data to the target,
posting a memory read of the additional memory write location from the initiator device to the target device, and
continuing operation of the initiator device when a completion is returned with a good status and data matching the additional memory write data from the target device to the initiator device.
7. The method of claim 1 , further comprising the steps of:
Posting an additional memory write with specific data to the target,
posting a memory read of the additional memory write location from the initiator device to the target device, and
halting operation of the initiator device when a completion is returned with at least one of an error status and data not matching the additional memory write data from the target device to the initiator device.
8. A method of verifying proper communication of data packets from one of a plurality of initiator devices on a PCIe data bus to one of a plurality of target devices on the data bus, the method comprising the steps of:
synchronizing a target-specific counter selected from a plurality of target-specific counters on the initiator device, where one each of the plurality of target-specific counters is associated with one each of the plurality of target devices on the data bus, and an initiator-specific counter selected from a plurality of initiator-specific counters on the target device, where one each of the plurality of initiator-specific counters is associated with one each of the plurality of initiator devices on the data bus, with a common counter value,
with the initiator device,
writing the counter value of the target-specific counter on the initiator device into a tag field of a header for the packet, and
writing an identifier of the initiator device into the packet header,
sending the packet from the initiator device to the target device on the PCIe data bus,
upon receipt of the packet by the target device, reading the identifier and checking the counter value written into the header of the packet with the initiator-specific counter on the target device,
when the counter value written into the header of the packet is not equal to the initiator-specific counter on the target device, then generating an error message with the target device,
posting an additional memory write with specific data to the target, posting a memory read of additional memory write location from the initiator device to the target device,
continuing operation of the initiator device when a completion is returned with a good status and data matching the additional memory write data from the target device to the initiator device, and
halting operation of the initiator device when the completion is returned with at least one of an error status and data not matching the memory write data from the target device to the initiator device.