Method and apparatus for internally trimming output drivers and terminations in semiconductor devices
First Claim
1. A method for trimming interface devices, which comprises:
- providing a semiconductor device having a plurality of interface devices and providing each one of the plurality of interface devices with a settable control element;
providing a test apparatus having a current source;
connecting the current source in the test apparatus to an interface connection on the semiconductor device, the interface connection being connected to one of the plurality of interface devices;
controlling a measurement current produced by the current source and setting the control element of the one of the plurality of interface devices to an initial value;
providing a trimming unit in the semiconductor device;
using the trimming unit to acquire a measurement voltage produced by the measurement current in the one of the plurality of interface devices;
using the trimming unit to compare the measurement voltage with a nominal voltage;
based on a difference between the measurement voltage and the nominal voltage, setting the control element of the one of the plurality of interface devices to a trimming value at which the measurement voltage matches the nominal voltage; and
acquiring the trimming value for the control element of the one of the plurality of interface devices.
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Accused Products
Abstract
To trim interface devices on semiconductor devices, such as trimmable output drivers and terminations, a measurement current produced in the test apparatus is impressed onto the interface device, and a measurement voltage produced by the measurement current in the interface device is detected by a trimming unit provided within the semiconductor device and is trimmed using control elements and trimming registers controlled by the trimming unit. To this end, the trimming unit ascertains trimming information which is stored in nonvolatile fashion in a memory unit in the semiconductor device and is loaded into the trimming registers in the semiconductor device whenever the semiconductor device is started up.
22 Citations
20 Claims
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1. A method for trimming interface devices, which comprises:
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providing a semiconductor device having a plurality of interface devices and providing each one of the plurality of interface devices with a settable control element;
providing a test apparatus having a current source;
connecting the current source in the test apparatus to an interface connection on the semiconductor device, the interface connection being connected to one of the plurality of interface devices;
controlling a measurement current produced by the current source and setting the control element of the one of the plurality of interface devices to an initial value;
providing a trimming unit in the semiconductor device;
using the trimming unit to acquire a measurement voltage produced by the measurement current in the one of the plurality of interface devices;
using the trimming unit to compare the measurement voltage with a nominal voltage;
based on a difference between the measurement voltage and the nominal voltage, setting the control element of the one of the plurality of interface devices to a trimming value at which the measurement voltage matches the nominal voltage; and
acquiring the trimming value for the control element of the one of the plurality of interface devices. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. A semiconductor device comprising:
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at least one interface device having a settable control element;
a trimming register connected to said control element; and
a trimming unit for writing to said trimming register based on a measured variable detected on said interface device;
said trimming unit connected to said interface device and said trimming register. - View Dependent Claims (15, 16, 17, 18, 19, 20)
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Specification