Granted Patent B2

US 8,775,705 · App. 13/853,978 · Granted Jul 8, 2014

Inventors: Mark A. Horowitz (Menlo Park, CA); Craig E. Hampel (Los Altos, CA); Alfredo Moncayo (Camarillo, CA); Kevin S. Donnelly (Los Altos, CA); Jared L. Zerbe (Woodside, CA)

Assignee: Rambus Inc.

Abstract

Claims (40)

1. An integrated circuit device comprising:

a transmitter circuit including an output driver;

a first register to store a value representative of a drive strength setting associated with the transmitter circuit such that the output driver outputs data in accordance with the drive strength setting;

a second register to store a value representative of an equalization setting associated with the transmitter circuit such that the output driver outputs data in accordance with the equalization setting; and

a third register to store a value representative of a slew rate setting associated with the transmitter circuit such that the output driver outputs data in accordance with the slew rate setting.

2. The integrated circuit device of claim 1 , wherein the transmitter circuit outputs data onto an external signal line, wherein the equalization setting compensates for a cross-coupled signal present on the external signal line.

3. The integrated circuit device of claim 1 , further including a data history generator circuit coupled to the transmitter circuit, to provide an adjustment to the drive strength setting based on data that was previously output by the output driver.

4. The integrated circuit device of claim 3 , wherein the data history generator includes a shift register to store data that was previously output by the output driver, wherein a voltage swing setting of the output driver is modified based on data that was previously output by the output driver.

5. The integrated circuit device of claim 1 , wherein the integrated circuit device is a memory device.

6. The integrated circuit device of claim 1 , wherein the integrated circuit device is a controller for controlling a memory device.

7. The integrated circuit device of claim 1 , wherein the integrated circuit device includes a locked loop circuit to generate a transmit clock signal, wherein the transmitter circuit outputs data using the transmit clock signal.

8. The integrated circuit device of claim 7 , further including a register to store a value representative of a transmit time adjustment that is applied to the transmit clock signal.

9. The integrated circuit device of claim 1 , further including a counter, coupled to the output driver, to hold a count value that is used to adjust the voltage swing of the output driver in accordance with a signal that indicates a direction to adjust the count value.

10. The integrated circuit device of claim 1 , further including:

a locked loop circuit to generate an internal transmit signal, wherein the transmitter circuit outputs data in response to the internal transmit signal; and

a register to store a value representative of a transmit timing offset to apply to the internal transmit signal.

11. The integrated circuit device of claim 1 , wherein the output driver is configured to output a same bit of data in accordance with the drive strength setting, the equalization setting, and the slew rate setting.

12. A method of operating an integrated circuit device comprising:

storing, in a first register of the integrated circuit device, a value representative of a drive strength setting associated with the transmitter circuit;

storing, in a second register of the integrated circuit device, a value representative of an equalization setting associated with the transmitter circuit;

storing, in a third register of the integrated circuit device, a value representative of a slew rate setting associated with the transmitter circuit; and

outputting data with an output driver of the integrated circuit device in accordance with the drive strength setting, the equalization setting, and the slew rate setting.

13. The method of claim 12 , wherein outputting data with the output driver includes outputting data onto an external signal line, wherein the equalization setting compensates form a cross-coupled signal present on the external signal line.

14. The method of claim 12 , further including providing an adjustment to the drive strength setting based on data that was previously output by the output driver.

15. The method of claim 14 , further including:

storing, in a shift register, data that was previously output by the output driver; and

modifying a voltage swing setting of the output driver based on data that was previously output by the output driver.

16. The method of claim 12 , wherein the integrated circuit device is a memory device.

17. The method of claim 12 , wherein the integrated circuit device is a controller for controlling a memory device.

18. The method of claim 12 , wherein outputting data with the output driver includes outputting data using a transmit clock signal generated by a locked loop circuit of the integrated circuit device.

19. The method of claim 18 , further including:

storing, in a timing register, a value representative of a transmit time adjustment; and

applying the value representative of the transmit time adjustment to the transmit clock signal.

20. The method of claim 12 , further including adjusting the voltage swing of the output driver by adjusting a count value of a counter that is coupled to the output driver.

21. The method of claim 12 , further including:

generating, with a locked loop circuit, an internal transmit signal;

outputting data in response to the internal transmit signal;

storing, in a timing register, a value representative of a transmit timing offset; and

applying the value representative of the transit timing offset to the internal transmit signal.

22. The method of claim 12 , wherein outputting data with the output driver includes outputting a same bit of data in accordance with the drive strength setting, the equalization setting, and the slew rate setting.

Assignments (1)

Continuity (12)