Method and apparatus for multi-level de-emphasis
AssigneeQUALCOMM Incorporated
InventorsMiao Li, Madjid Hafizi, Xiaohua Kong
Life of this patent
Estimating the term…
Abstract
A distribution current is split into a first control current, a second control current, and a third control current, in an apportionment according to a distribution command. A first control voltage is generated in response to the third control current. A second control voltage is generated as indication of the first control current, and a third control voltage is generated as indication of the second control current. Optionally, de-emphasis contribution of a first driver, a second driver and a third driver to an output is controlled based, at least in part, on the first control voltage, the second control voltage and the third control voltage, respectively.
Claims43
An apparatus for distributing current, comprising:
- a current source configured to generate a total distribution current (TDC);
- a programmable current splitter configured to split the TDC, in an apportionment according to a given distribution command, into a first control current, a second control current, and a third control current;
- a first current indicating circuit configured to generate a first control voltage indicative of the third control current;
- a second current indicating circuit configured to generate a second control voltage indicative of the first control current;
- and
- a third current indicating circuit configured to generate a third control voltage indicative of the second control current.
An apparatus for selective de-emphasis driving an embedded display port, comprising:
- a current source configured to generate a total distribution current (TDC);
- a programmable current splitter configured to split the TDC, in an apportionment according to a given distribution command, into a first control current, a second control current, and a third control current;
- a first current indicating circuit configured to generate a first control voltage at a value corresponding to the third control current;
- a second current indicating circuit configured to generate a second control voltage at a value corresponding to the first control current;
- a third current indicating circuit configured to generate a third control voltage at a value corresponding to the second control current;
- a main driver having a current source coupled to the first control voltage, and configured to receive an input signal and to output, in response, a non-emphasis signal on the embedded display port;
- a first post-tap de-emphasis driver having a second current source coupled to the second control voltage, and configured to receive a first post-tap input signal and to output, in response, a first post-tap de-emphasis signal on the embedded display port;
- and
- a second post-tap de-emphasis driver having a third current source coupled to the third control voltage, and configured to receive a second post-tap input signal and to output, in response, a second post-tap de-emphasis signal on the embedded display port.
A method for apportioning control voltages to a plurality of drivers in parallel, comprising:
- receiving a distribution command;
- generating a distribution current;
- splitting the distribution current into a first control current, a second control current, and a third control current, in an apportionment according to the distribution command, wherein the third control current is a remaining portion of the distribution current after splitting into the first control current and the second control current;
- generating a first control voltage indicative of the third control current;
- generating a second control voltage indicative of the first control current;
- and
- generating a third control voltage indicative of the second control current.
(canceled)
(canceled)
An apparatus for apportioning contribution by a plurality of drivers in parallel comprising:
- means for generating a distribution current;
- means for receiving a distribution command;
- means for splitting the distribution current into a first control current, a second control current, and a third control current, in an apportionment according to the distribution command, wherein the third control current is a remaining portion of the distribution current after splitting into the first control current and the second control current
- means for generating a first control voltage indicative of the third control current;
- means for generating a second control voltage indicative of the first control current;
- and
- means for generating a third control voltage indicative of the second control current.
A method for apportioning control voltages to a plurality of drivers in parallel comprising:
- step for receiving a distribution command;
- step for generating a distribution current;
- step for splitting the distribution current into a first control current, a second control current, and a third control current, in an apportionment according to the distribution command, wherein the third control current is a remaining portion of the distribution current after splitting into the first control current and the second control current;
- step for generating a first control voltage indicative of the third control current;
- step for generating a second control voltage indicative of the first control current;
- and
- step for generating a third control voltage indicative of the second control current.
(canceled)
A computer-readable medium comprising instructions, which, when executed by a processor apparatus, cause the processor apparatus to perform operations carrying out a method for apportioning control voltages to a plurality of drivers in parallel, comprising instructions that cause the processor apparatus to:
- receive a distribution command;
- generate a distribution current;
- split the distribution current into a first control current, a second control current, and a third control current, in an apportionment according to the distribution command, wherein the third control current is a remaining portion of the distribution current after splitting into the first control current and the second control current;
- generate a first control voltage indicative of the third control current;
- generate a second control voltage indicative of the first control current;
- and
- generate a third control voltage indicative of the second control current.
(canceled)
Dependencies are inferred from the claim text.