CROSS-FEEDBACK PHASE-LOCKED LOOP FOR DISTRIBUTED CLOCKING SYSTEMS
First Claim
Patent Images
1. An apparatus comprising:
- a first domain having a first phase-locked loop (PLL);
a second domain having a second PLL, the second domain being adjacent to the first domain, whereinthe first PLL is configured to receive a first input from an output of the first PLL and a second input from an output of the second PLL, andthe second PLL is configured to receive a third input from the output of the first PLL and a fourth input from the output of the second PLL to form a cross feedback relationship between the first PLL and the second PLL.
1 Assignment
0 Petitions
Accused Products
Abstract
According to various embodiments, a cross-feedback phase-locked loop (XF-PLL) may include a secondary phase/frequency detector to detect the phase/frequency differences between two adjacent domains and feed the phase/frequency differences back into the main feedback loop of the XF-PLL, thereby reducing accumulated jitter and inter-domain clock skew in a distributed clocking system. Other embodiments may be described and claimed.
28 Citations
22 Claims
-
1. An apparatus comprising:
-
a first domain having a first phase-locked loop (PLL); a second domain having a second PLL, the second domain being adjacent to the first domain, wherein the first PLL is configured to receive a first input from an output of the first PLL and a second input from an output of the second PLL, and the second PLL is configured to receive a third input from the output of the first PLL and a fourth input from the output of the second PLL to form a cross feedback relationship between the first PLL and the second PLL. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. A method comprising:
-
receiving, by a secondary phase frequency detector unit disposed on an integrated circuit comprising multiple domains, a first input signal based on an output of a main phase-locked loop (PLL) of a first domain and a second input signal based on an output of a second PLL of a second domain, the second domain being adjacent to the first domain; detecting, by the secondary phase or frequency detection unit, a phase or frequency difference between the first and the second input signal; and adjusting the output of the main PLL at least partially based on detected phase or frequency difference. - View Dependent Claims (12, 13, 14, 15)
-
-
16. A system comprising:
-
a memory controller disposed on a die; a plurality of execution units disposed on a die coupled to the memory controller, wherein respective ones of the plurality of execution units are adjacent to one or more neighboring executing units and the respective ones of the plurality of execution units further comprise a cross-feedback phase-locked loop (XF-PLL) configured to receive a main input from an output of the XF-PLL and one or more secondary inputs respectively from one or more outputs of one or more XF-PLL'"'"'s of the corresponding one or more neighboring execution units. - View Dependent Claims (17, 18, 19, 20, 21, 22)
-
Specification