US 6,606,666 B1 · Method and system for controlling information flow between a producer and a buffer in a high frequency digital system

Abstract

An information handling system includes a producer that outputs packets, a buffer that receives packets from the producer, buffers the packets, and eventually outputs the packets, and a control unit that controls the flow of packets from the producer to the buffer. The control unit receives as inputs a producer output indication indicating that the producer has output a packet to the buffer and a buffer output indication indicating that the buffer has output a packet. Based upon a capacity of the buffer, a number of the producer output indications, a number of buffer output indications, and a number of grant messages output to the producer within a feedback latency of the control unit, the control unit whether the producer can output a packet without packet loss. In response to a determination that the producer can output a packet without packet loss, the control unit outputs a grant message to the producer indicating that the producer is permitted to output a packet.

Claims22

Dependent claims

A method for controlling packet flow from a producer to a buffer, said method comprising:

receiving as inputs at a control unit one or more producer output indications each indicating that said producer has output a respective packet to said buffer via a data path and one or more buffer output indications each indicating that said buffer has output a respective packet;
at said control unit, determining whether said producer can output a packet via said data path without packet loss, based upon a capacity of said buffer, how many packets have been output by said producer based upon said producer output indications, how many packets have been output by said buffer based upon said buffer output indications, and how many packets said control unit has authorized said producer to output based upon grant messages output to said producer within a feedback latency of said control unit, wherein said feedback latency includes a first latency for a producer output indication to reach said control unit from said producer and a second latency for a grant message to reach said producer from said control unit;
and
in response to a determination that said producer can output a packet without packet loss, said control unit generating and outputting a grant message to said producer via a control path physically separate from said data path, said grant message indicating that said producer is authorized to output a packet.

1 more element

An information handling system, comprising:

a producer that outputs packets of information via a data path;
a buffer, coupled to said data path, that receives said packets from said producer and outputs said packets;
and
a control unit coupled to said producer by a control path physically separate from said data path, wherein said control unit receives one or more producer output indications each indicating that said producer has output a respective packet and receives one or more buffer output indications each indicating that said buffer has output a respective packet, wherein said control unit determines whether said producer can output a packet via said data path without packet loss, based upon a capacity of said buffer, how many packets have been output by said producer based upon said producer output indications, how many packets have been output by said buffer based upon said buffer output indications, and how many packets said control unit has authorized said producer to output based upon grant messages output to said producer within a feedback latency of said control unit, and wherein said control unit, responsive to a determination that said producer can output a packet without packet loss, generates and outputs a grant message to said producer via said control path, said grant message indicating that said producer is authorized to output a packet,
wherein said feedback latency comprises a first latency for a producer output indication to reach said control unit from said producer and a second latency for a grant message to reach said producer from said control unit via said control path.

2 more elements

A controller for controlling packet transfer from a producer that outputs packets of information on a data path to a buffer that receives said packets from said producer and thereafter outputs said packets, said controller comprising:

a first input that receives one or more producer output indications each indicating that the producer has output a respective packet on said data path and a second input that receives one or more buffer output indications each indicating that the buffer has output a respective packet;
an output coupled to said producer by a control path physically separate from said data path;
and
determination logic that determines whether said producer can output a packet on said data path without packet loss, based upon a capacity of said buffer, how many packets said producer has output as indicated by said producer output indications, how many packets said buffer has output as indicated by buffer output indications, and how many packets said controller has authorized said producer to output as indicated by grant messages output to said producer within a feedback latency of said controller, wherein said determination logic, in response to determining that said producer can output a packet via said data path without packet loss, generates and outputs a grant message to said producer via said control path, said grant message indicating that said producer is authorized to output a packet,
wherein said feedback latency comprises a first latency for a producer output indication to reach said controller from said producer and a second latency for a grant message to reach the producer from said controller via said control path.

2 more elements

A program product for controlling packet transfer from a producer that outputs packets of information on a data path to a buffer that receives said packets from said producer and outputs said packets, said program product comprising:

input code that obtains one or more producer output indications each indicating that the producer has output a respective packet and one or more buffer output indications each indicating that the buffer has output a respective packet;
determination code that determines whether said producer can output a packet on said data path without packet loss, based upon a capacity of said buffer, how many packets said producer has output as indicated by said producer output indications, how many packets said buffer has output as indicated by said buffer output indications, and how many packets said producer has been authorized to output as indicated by grant messages output to said producer within a control feedback latency, wherein said determination code, responsive to determining that said producer can output a packet on said data path without packet loss, generates and outputs a grant message to said producer via a control path physically separate from said data path, said grant message indicating that said producer is authorized to output a packet,
wherein said control feedback latency comprises a first latency for said producer output indication to be received by said input code and a second latency for a grant message to reach the producer from said determination code via said control path;
and
a computer-usable medium encoding said input code and said determination code.

2 more elements

Dependencies are inferred from the claim text.

Method and system for controlling information flow between a producer and a buffer in a high frequency digital system

Life of this patent

Method and system for controlling information flow between a producer and a buffer in a high frequency digital system

Life of this patent

Abstract

Claims22