Devices and methods for transmission of events with a uniform latency on serial communication links
View Patent ↗The present disclosure relates generally to serial communication links and, more specifically, to events communicated on serial communication links and the timing of those events, for example, to achieve uniform delay among multiple event transmissions.
1. A serial communication link, comprising:
a transmitter and a receiver configured to define a uniform latency between a transmitter-side event and a receiver-side event;
the transmitter comprising:
delay circuitry configured to receive the transmitter-side event and delay the transmitter-side event by a delay time corresponding to a frame length; and
control circuitry configured to prevent additional frames from being started while the transmitter-side event is being delayed; and
transmission circuitry configured to send an event frame corresponding to the transmitter-side event after the delay time, wherein the transmission circuitry is configured to include, in the event frame, event identifier bits indicative that the frame being transmitted is an event frame; and
the receiver comprising:
receive circuitry configured to:
decode the frame being transmitted as the event frame; and
assert the receiver-side event responsive to the decoding.
2. The serial communication link of claim 1 , wherein the delay circuitry comprises a shift register of a size corresponding to a number of bits corresponding to the frame length.
3. The serial communication link of claim 1 , wherein the delay circuitry comprises a counter and a register, the counter configured to count a number corresponding to a number of bits corresponding to the frame length.
4. The serial communication link of claim 1 , wherein the transmission circuitry is configured to encode frames based on a protocol selected from a group consisting of a Universal Asynchronous Receiver/Transmitter, a Universal Synchronous Receiver/Transmitter, or a Universal Synchronous/Asynchronous Receiver/Transmitter.
5. The serial communication link of claim 1 , wherein the receive circuitry is configured to decode frames based on a protocol selected from a group consisting of a Universal Asynchronous Receiver/Transmitter, a Universal Synchronous Receiver/Transmitter, or a Universal Synchronous/Asynchronous Receiver/Transmitter.
6. The serial communication link of claim 1 , wherein the delay time is as long as one frame length.
7. The serial communication link of claim 1 , wherein a duration of the uniform latency is a fixed delay specified at the transmitter and at the receiver.
8. The serial communication link of claim 1 , wherein a duration of the uniform latency is communicated from the transmitter to the receiver.
9. The serial communication link of claim 1 , wherein a duration of a period of time from the occurrence of the transmitter-side event to the assertion of the receiver-side event corresponds to the uniform latency.
10. The serial communication link of claim 1 , wherein the assertion of the receiver-side event occurs a duration of the uniform latency after the occurrence of the transmitter-side event.
11. A serial communication link, comprising:
a transmitter and a receiver configured to define a uniform latency between a transmitter-side event and a receiver-side event;
the transmitter comprising:
delay circuitry configured to receive the transmitter-side event and delay the transmitter-side event by a delay time corresponding to a frame time; and
control circuitry configured to prevent additional frames from being started while the transmitter-side event is being delayed; and
transmission circuitry configured to send an event frame corresponding to the transmitter-side event after the delay time, wherein the transmission circuitry is configured to include, in the event frame: event identifier bits indicative that the frame being transmitted is an event frame and one or more error bits indicating whether the event indicator was delayed for a period of time longer than the frame time; and
the receiver comprising:
receive circuitry configured to:
decode the frame being transmitted as the event frame; and
assert the receiver-side event responsive to the decoding.
12. A method of communicating on a serial communication link, comprising:
obtaining, at a transmitter, a transmitter-side event at a first time;
delaying, at the transmitter, the transmitter-side event for a delay time, the duration of the delay time corresponding to a frame length;
preventing, at the transmitter, additional frames from being transmitted during the delay time;
transmitting an event frame corresponding to the transmitter-side event after the delay time, the event frame including event-identifier bits indicative that the event frame is an event frame;
receiving, at a receiver, the event frame; and
asserting, at the receiver, a receiver-side event at a second time, the second time being a fixed delay time after the first time.
13. The method of claim 12 , further comprising:
obtaining, at the transmitter, a second transmitter-side event at a third time;
delaying, at the transmitter, the second transmitter-side event for a second delay time, the duration of the second delay time corresponding to the frame length;
preventing, at the transmitter, additional frames from being transmitted during the second delay time;
transmitting a second event frame corresponding to the second transmitter-side event after the second delay time, the second event frame including second event-identifier bits indicative that the second event frame is an event frame;
receiving, at the receiver, the second event frame; and
asserting, at the receiver, a second receiver-side event at a fourth time, the fourth time being the fixed delay time after the third time.