Memory controller, memory circuit and memory system with a memory controller and a memory circuit
View Patent ↗Methods and apparatus for adjusting a phase difference between clock signals. A first clock signal at a memory controller is adjusted relative to a clock second signal at a memory device. In one embodiment, data is transferred to the memory device according to the first clock signal, which has a predetermined phase relationship with second clock signal. Data received at the memory device is sampled at the memory device according to the second clock signal. Analysis is done of the data on the memory controller and of the received data on the memory circuit. On the basis of the analysis, an adjustment may be made to the phase relationship.
1. A memory controller, comprising:
a first data interface for at least sending data to a memory circuit;
a masking circuit;
a data providing circuit that is connected with the first data interface and the masking circuit; wherein the data providing circuit is configured to deliver same data to the first data interface and to the masking circuit; wherein the first data interface outputs the data received from the data providing circuit with a predetermined time position relative to a reference time;
an error detection circuit connected with the masking circuit; wherein the masking circuit masks parts of the data and delivers at least a non masked part of the data to the error detection circuit; wherein the error detection circuit calculates a first error result using the received non masked data;
an analyzing comparing circuit connected with the error detection circuit and configured to receive the first error result; wherein the analyzing circuit is configured to receive a second error result of the memory circuit; wherein the analyzing circuit analyzes the first and second error result to produce correlation information; and
a controlling circuit configured to receive the correlation information; the controlling circuit being configured to control the time position of the output of the data by the first data interface relative to the reference time on the basis of the correlation information.
2. The memory controller of claim 1 , further comprising a second data interface for receiving data from the memory circuit.
3. The memory controller of claim 2 , wherein the analyzing circuit is connected with the second interface and receives the second error result of the memory circuit from the second interface.
4. The memory controller of claim 1 , wherein the masking circuit selects one data bit and masks other data bits, the one data bit being the non masked part of the data provided to the error detection circuit.
5. The memory controller of claim 1 , wherein the providing circuit is connected with a predetermined number of data channels in parallel with the masking circuit, wherein the masking circuit is connected with a predetermined number of data channels with the error detection circuit, wherein the masking circuit selects at least one data channel and masks the other data channels.
6. The memory controller of claim 1 , wherein the masking circuit masks data by replacing a value of a masked bit of the data with a predetermined value and delivers the predetermined value of the masked data and the non masked data to the error detection circuit.
7. The memory controller of claim 1 , wherein the masking circuit is connected with a command circuit; the masking circuit receives a control command that specifies a masking method that is used by the masking circuit.
8. The memory controller of claim 7 , wherein the masking circuit is connected by data channels with the error detection circuit, wherein according to the specified masking method the masking circuit masks only one of the data channels.
9. The memory controller of claim 7 , wherein according to the specified masking method only one predetermined data bit of the data is not masked.
10. The memory controller of claim 1 , wherein the controller circuit adjusts the time position of the data output by the first data interface relative to the reference time to a time position at which the correlation information of the analyzing circuit indicates a predetermined correlation between the first and second error result.
11. The memory controller of claim 1 , wherein the correlation information is a pass indication indicating that the first and second error result are equal or a failure indication indicating that the first and second error result are different.
12. The memory controller of claim 1 , wherein the error detection circuit is a cyclic redundancy calculation circuit.
13. The memory controller of claim 1 , wherein the memory controller sends a masking control command to the memory circuit specifying a method to mask data before performing an error detection calculation generating the second error result in the memory circuit.
14. The memory controller of claim 13 , wherein the control command determines with a data pattern which of the received data are to be masked.
15. The memory controller of claim 1 , wherein the masking circuit is connected with a mode register that determines which of the received data are to be masked.
16. A memory system, comprising:
a memory controller and a memory circuit coupled to each other;
wherein the memory controller comprises:
a first data interface for at least sending data to a memory circuit;
a first masking circuit;
a data providing circuit that is connected with the first data interface and the first masking circuit; wherein the data providing circuit is configured to deliver same data to the first data interface and to the first masking circuit; wherein the first data interface outputs the data received from the data providing circuit with a predetermined time position relative to a reference time;
a first error detection circuit connected with the first masking circuit;
wherein the first masking circuit masks parts of the data and delivers at least a non masked part of the data to the first error detection circuit; wherein the first error detection circuit calculates a first error result using the received non masked data; and
an analyzing circuit connected with the first error detection circuit and configured to receive the first error result; wherein the analyzing circuit is configured to receive a second error result from the memory circuit; wherein the analyzing circuit analyzes the first and second error result to produce correlation information; and
a controlling circuit configured to receive the correlation information; the controlling circuit being configured to control the time position of the output of the data by the first data interface relative to the reference time on the basis of the correlation information; and
wherein the memory circuit comprises:
memory elements for storing data;
a second data interface for at least receiving data from the memory controller, buffering the data, sampling the buffered data according to a reference time and outputting the sampled data;
a second masking circuit connected with the second data interface to receive the output data, and configured to mask a part of the data and output at least a part of the non masked data; and
a second error detection circuit connected with the second masking circuit to receive the non-masked data and output the second error result which is returned to the analyzing circuit.
17. The memory system of claim 16 , wherein the memory controller further comprises a command circuit coupled to the first and masking circuits via a command line; the command circuit determining a method of masking performed by the first and second masking circuits.