Direct-input redundancy scheme with adaptive syndrome decoder
Methods, systems, and devices for operating memory cell(s) using a direct-input column redundancy scheme are described. A device that has read data from data planes may replace data from one of the planes with redundancy data from a data plane storing redundancy data. The device may then provide the redundancy data to an error correction circuit coupled with the data plane that stored the redundancy data. An output of the error correction circuit may be used to generate syndrome bits, which may be decoded by a syndrome decoder. The syndrome decoder may indicate whether a bit of the data should be corrected by selectively reacting to inputs based on the type of data to be corrected. For example, the syndrome decoder may react to a first set of inputs if the data bit to be corrected is a regular data bit, and react to a second set of inputs if the data bit to be corrected is a redundant data bit.
1. An apparatus, comprising:
error correction code (ECC) circuits coupled with data planes and configured to receive data bits from the data planes and generate first error correction information based on at least the received data bits;
a redundant ECC circuit coupled with a redundant data plane and configured to receive, from the redundant data plane, redundant data that corresponds to data stored by at least one of the data planes and generate second error correction information based on at least in part on the redundant data; and
a syndrome decoder circuit, for a first data plane of the data planes, that is coupled with the redundant ECC circuit and the ECC circuits and that is configured to generate an output based on at least in part on whether the redundant data received by the redundant ECC circuit corresponds to data stored by at least the first data plane, and based on at least in part on one or more of the first error correction information or the second error correction information.
2. The apparatus of claim 1 , wherein the syndrome decoder circuit is configured to receive a first set of syndrome-based inputs and a second set of syndrome-based inputs, and wherein the syndrome decoder circuit is configured to generate the output by being configured to nullify the first set of syndrome-based inputs when the redundant data corresponds to data stored by the first data plane and nullify the second set of syndrome-based inputs when the redundant data corresponds to data stored by a data plane other than the first data plane.
3. The apparatus of claim 1 , wherein the syndrome decoder circuit comprises a first logic gate and a second logic gate that are each configured to receive syndrome-based inputs comprising syndrome bits or inverted syndrome bits or a combination thereof and perform bitwise operations on the received syndrome-based inputs.
4. The apparatus of claim 3 , further comprising:
an inverter comprising an input coupled with the first logic gate of the syndrome decoder circuit and an output coupled with the second logic gate of the syndrome decoder circuit, the inverter configured to output, to the second logic gate, a signal indicating whether the redundant data is corresponds to data stored by the first data plane.
5. The apparatus of claim 3 , wherein the output of the syndrome decoder circuit indicates whether a bit from the first data plane or the redundant data plane is to be inverted based on at least in part on the syndrome-based inputs for the first logic gate and independent of the syndrome-based inputs for the second logic gate when the redundant data is for the first data plane.
6. The apparatus of claim 3 , wherein the output of the syndrome decoder circuit indicates whether a bit from the first data plane or the redundant data plane is to be inverted based on at least in part on the syndrome-based inputs for the second logic gate and independent of the syndrome-based inputs for the first logic gate when the redundant data is for a data plane other than the first data plane.
7. The apparatus of claim 1 , further comprising:
a bit flipping circuit coupled with the syndrome decoder circuit and configured to invert a bit from the first data plane or the redundant data plane based on at least in part on the output of the syndrome decoder circuit.
8. The apparatus of claim 1 , wherein the redundant ECC circuit comprises a set of logic gates configured to perform bitwise operations on the redundant data, and wherein each of the ECC circuits comprises a set of logic gates configured to perform bitwise operations on data from the respective data plane.