IP Library Granted Patent US 8,458,385
Granted Patent B2
US 8,458,385 · App. 13/535,228 · Granted Jun 4, 2013

Chip having register to store value that represents adjustment to reference voltage

Inventors: Mark A. Horowitz (Menlo Park, CA); Richard M. Barth (Palo Alto, CA); Craig E. Hampel (San Jose, CA); Alfredo Moncayo (Redwood City, CA); Kevin S. Donnelly (Los Altos, CA); Jared L. Zerbe (Woodside, CA)
Assignee: Rambus Inc.
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Quick Facts
Patent No.
US 8,458,385
App. No.
13/535,228
Granted
Jun 4, 2013
Kind
B2
Abstract

A chip includes a receiver circuit that uses a reference voltage to receive a data signal such that a logic level of the received data signal is determined using the reference voltage, and a register to store a value that represents an adjustment to the reference voltage.

Claims (41)

1. A chip comprising:

a receiver circuit that uses a reference voltage to receive a data signal such that a logic level of the received data signal is determined using the reference voltage; and

a register to store a value that represents an adjustment to the reference voltage.

2. The chip of claim 1 , wherein the value stored by the register is a topology dependent parameter value.

3. The chip of claim 1 , where the receiver circuit comprises:

threshold control circuitry to generate the reference voltage based on the value stored in the register; and

a comparator circuit to compare the reference voltage and the received data signal.

4. The chip of claim 3 , where the threshold control circuitry generates the reference voltage based on a baseline reference voltage and the value stored in the register.

5. The chip of claim 3 , where the threshold control circuitry comprises:

a digital-to-analog converter to produce an analog voltage; and

a summing amplifier to generate the reference voltage by summing the analog voltage with a baseline reference voltage.

6. The chip of claim 3 , further comprising timing circuitry to synchronize the output of the comparator circuit with a clock signal.

7. The chip of claim 6 , wherein the register comprises a first register, the chip further comprising:

a second register to store a second value; and

a locked loop circuit to generate the clock signal based at least in part on the second value.

8. The chip of claim 3 , further comprising an equalizer circuit to generate an equalization offset value based on the output of the comparator circuit.

9. The chip of claim 8 , further comprising an adder circuit to add the equalization offset value to the reference voltage before the reference voltage is received by the comparator circuit.

10. The chip of claim 8 , further comprising an adder circuit to add the equalization offset value to the received data signal before the data signal is received by the comparator circuit.

11. The chip of claim 1 , wherein the chip is a memory controller device.

12. The chip of claim 1 , wherein the chip is a memory device.

13. A method of operation of a chip including a receiver circuit and a register, the method comprising:

storing in the register a value that represents an adjustment to a reference voltage; and

at the receiver circuit, receiving a data signal such that a logic level of the received data signal is determined using the reference voltage.

14. The method of claim 13 , wherein the value stored by the register is a topology dependent parameter value.

15. The method of claim 13 , including adjusting one or more characteristics of the received data signal based at least in part on the value stored in the register.

16. The method of claim 13 , further comprising:

generating the reference voltage based on the value stored in the register; and

comparing the received data signal with the reference voltage.

17. The method of claim 16 , wherein generating the reference voltage comprises generating the reference voltage based on a baseline reference voltage and the value stored in the register.

18. The method of claim 16 , wherein generating the reference voltage comprises:

converting the value stored in the register using digital-to-analog conversion to produce an analog voltage; and

summing the analog voltage with a baseline reference voltage to generate the reference voltage.

19. The method of claim 16 , further comprising synchronizing the output of the comparator circuit with a clock signal.

20. The method of claim 19 , wherein the register comprises a first register, the method further comprising:

storing in a second register a second value; and

generating the clock signal based at least in part on the second value.

21. The method of claim 16 , further comprising generating an equalization offset value based on an output produced by comparing the received data signal with the reference voltage.

22. The method of claim 21 , further comprising adding the equalization offset value to the reference voltage to produce an adjusted reference voltage and comparing the received data signal with the adjusted reference voltage.

23. The method of claim 21 , further comprising adding the equalization offset value to the received data signal before the data signal is received by a comparator circuit.

24. The method of claim 13 , wherein the chip is a memory controller device.

25. The method of claim 13 , wherein the chip is a memory device.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Apr 16, 2015
From: HOROWITZ, MARK A.; BARTH, RICHARD M.; HAMPEL, CRAIG E.; MONCAYO, ALFREDO; DONNELLY, KEVIN S.; ZERBE, JARED L.
To: RAMBUS INC.
Reel/Frame 035424/0548 →
Continuity (11)
Continuation 13196840 · Aug 2, 2011
Continuation 12479679 · Jun 5, 2009
Continuation 11929974 · Oct 30, 2007
Continuation 11672018 · Feb 6, 2007
Continuation 11181411 · Jul 13, 2005
Continuation 11073403 · Mar 4, 2005
Continuation 10742247 · Dec 19, 2003
Continuation 10359061 · Feb 4, 2003
Continuation 09910217 · Jul 19, 2001
Continuation 09420949 · Oct 19, 1999
Related Publication 20120268199A1 · Oct 25, 2012