Method and system for receiver detection in PCI-Express devices
View Patent ↗A method and system for detecting when a receiver in a host system is present or absent to receive information from a PCI-Express device is provided. The method includes monitoring a signal received from a serial/de-serializer for transitions; re-starting a first timer when a transition is detected; and detecting a receiver's absence if a second timer has reached a maximum value after a transition is detected and a first timer cycle is incomplete. The PCI-Express device includes a receiver detection logic that determines when a receiver is absent before sending any data to the host system. The PCI-Express device may be a host adapter.
1. A method for detecting when a receiver in a PCI-Express device is present or absent to receive information, comprising:
monitoring a signal received from a serial/de-serializer for transitions;
re-starting a first timer when a transition is detected; and
detecting a receiver's absence if a second timer has reached a maximum value after a transition is detected and a first timer cycle is incomplete.
2. The method of claim 1 , wherein a first timer output value is compared to a programmed value and if the first timer output value is equal to the programmed value then a receiver is presumed to be present.
3. The method of claim 1 , wherein a second timer output value is compared to a programmed value and when the second timer output value is not equal to the programmed value, a signal is produced to declare a receiver's absence.
4. The method of claim 3 , wherein if the second timer output value is equal to the programmed value, then a receiver is presumed to be present.
5. The method of claim 1 , wherein if a transition is not detected then an edge detector continues to monitor the signal received from the serial/de-serializer.
6. The method of claim 1 , wherein if a transition is not detected, then a receiver is presumed to be present.
7. The method of claim 1 , wherein an output control module generates a signal to declare if a receiver is present or absent.
8. The method of claim 1 , wherein the PCI-Express device is a host bus adapter.
9. A PCI-Express device, comprising:
receiver detection logic that determines when a receiver is absent before sending any data to another PCI-Express device;
wherein an edge detector module monitors a signal received from a serial de-serializer for any transitions; and
if a transition is detected, a first timer is re-started; and
a second timer is used to declare that a receiver is absent when the first timer's cycle is incomplete after a certain time interval.
10. The PCI-Express device of claim 9 , wherein the time interval is programmable.
11. The PCI-Express device of claim 9 , wherein an output control module receives an input based on a comparison of a second timer value and a programmed value and declares that a receiver is absent when the second timer value is equal to the programmed value.
12. A system for connecting host systems with storage devices comprising:
a PCI-Express device with a receiver detection logic that determines when a receiver is absent before sending any data to a host system;
wherein an edge detector module monitors a signal received from a serial de-serializer for any transitions; and
if a transition is detected, a first timer is re-started; and
a second timer is used to declare that a receiver is absent when the first timer's cycle is incomplete after a certain time interval.
13. The system of claim 12 , wherein the time interval is programmable.