Application processors and electronic devices including the same

1. An application processor comprising:

a memory interface connected to a semiconductor memory device through first data input/output (I/O) pads and second data I/O pads; and

a memory controller configured to exchange data with the semiconductor memory device by controlling the memory interface, wherein:

the memory interface includes a training circuit configured to perform duty training of first data signals and second data signals which are based on the data, based on a reception control code set, by:

adjusting a duty of each of the first data signals with respect to a first reference voltage, the first data signals received through the first data I/O pads; and

adjusting a duty of each of the second data signals with respect to a second reference voltage, the second data signals received through the second data I/O pads.

2. The application processor of claim 1 , wherein the memory interface includes:

a data reception circuit connected to the first data I/O pads and the second data I/O pads, the data reception circuit including:

first receivers, each configured to receive a respective one of the first data signals from the semiconductor memory device; and

second receivers, each configured to receive a respective one of the second data signals from the semiconductor memory device; and

a data transmission circuit connected to the first data I/O pads and the second data I/O pads, the data transmission circuit including:

first transmitters, each configured to transmit a respective one of the first data signals to the semiconductor memory device; and

second transmitters, each configured to transmit a respective one of the second data signals to the semiconductor memory device.

3. The application processor of claim 2 , wherein each of the first receivers includes:

a comparator configured to compare a respective one of the first data signals with the first reference voltage to output a comparison signal and configured to adjust the duty of the respective one of the first data signals in response to the reception control code set; and

a data sampler configured to sample the comparison signal based on a data strobe signal to output a target data bit.

4. The application processor of claim 3 , wherein the comparator includes:

a sense amplifier configured to compare the respective one of the first data signals with the first reference voltage to output a comparison signal;

a first adjusting circuit, connected between in parallel with a first transistor to receive the respective one of the first data signals between a first node and a second node, the first adjusting circuit configured to control a first current provided to the second node in response to a first sub control code of the reception control code set; and

a second adjusting circuit, connected between in parallel with a first transistor to receive the first reference voltage between the first node and a third node, the second adjusting circuit configured to control a second current provided to the third node in response to a second sub control code of the reception control code set.

5. The application processor of claim 2 , further comprising:

an on-chip memory connected to the memory interface, wherein:

the training circuit is configured to:

calculate eye opening values of the first data signals and the second data signals at each of an initial value through a final value of possible combinations of the reception control code set by sweeping the possible combinations from the initial value to the final value; and

store the eye opening values in the on-chip memory with a table form.

6. The application processor of claim 5 , wherein the memory controller is configured to use a control code associated with an eye opening value having a maximum value among the eye opening values in a normal read operation with the semiconductor memory device.

7. The application processor of claim 2 , wherein the training circuit is configured to adjust duty of the first data signals and the second data signals when the data transmission circuit transmits the first data signals and the second data signals based on a transmission control code set.

8. The application processor of claim 7 , wherein each of the first transmitters includes:

a pull-up/pull-down control circuit configured to generate first and second pull-up control signals and first and second pull-down control signals based on a target data bit and the transmission control code set; and

a driver circuit configured to drive the target data bit based on the first and second pull-up control signals and the first and second pull-down control signals to output the respective one of the first data signals.

9. The application processor of claim 7 , further comprising:

an on-chip memory connected to the memory interface, wherein:

the training circuit is configured to:

calculate eye opening values of the first data signals and the second data signals at each of an initial value through a final value of possible combinations of the transmission control code set by sweeping the possible combinations from the initial value to the final value; and

store the eye opening values in the on-chip memory with a table form, and

the memory controller is configured to use a control code associated with an eye opening value having a maximum value among the eye opening values in a normal write operation with the semiconductor memory device.

10. The application processor of claim 1 , wherein the training circuit is configured to perform the duty training in an initialization operation after power is applied to the application processor.

11. The application processor of claim 10 , wherein:

in response to the application processor being rebooted after the initialization operation is performed for a first time, the training circuit is configured to:

load training data that was previously obtained and stored in an on-chip memory in the application processor; and

perform data read operation and data write operation on the semiconductor memory device based on the loaded training data.

12. The application processor of claim 10 , wherein:

in response to the application processor being rebooted after the initialization operation is performed for a first time, the training circuit is configured to:

load training data that was previously obtained and stored in an on-chip memory in the application processor; and

perform the duty training in response to the loaded training data being abnormal.

13. An electronic device comprising:

a semiconductor memory device configured to store data; and

an application processor configured to control the semiconductor memory device, wherein:

the application processor includes:

a memory interface connected to the semiconductor memory device through first data input/output (I/O) pads and second data I/O pads; and

a memory controller configured to exchange the data with the semiconductor memory device by controlling the memory interface,

the memory interface includes a training circuit configured to perform duty training of first data signals and second data signals which are based on the data, based on a reception control code set, by:

adjusting a duty of each of the first data signals with respect to a first reference voltage, the first data signals received through the first data I/O pads; and

adjusting a duty of each of the second data signals with respect to a second reference voltage, the second data signals received through the second data I/O pads.

14. The electronic device of claim 13 , wherein:

in a training sequence of the electronic device, the training circuit is configured to:

set the first reference voltage associated with the first data signals and the second reference voltage associated with the second data signals by performing a reference voltage training;

perform the duty training on the first data signals at the first reference voltage, which is fixed; and

perform the duty training on the second data signals at the second reference voltage, which is fixed.

15. The electronic device of claim 13 , wherein the memory interface includes:

a data reception circuit connected to the first data I/O pads and the second data I/O pads, the data reception circuit including:

first receivers, each configured to receive a respective one of the first data signals from the semiconductor memory device; and

second receivers, each configured to receive a respective one of the second data signals from the semiconductor memory device; and

a data transmission circuit connected to the first data I/O pads and the second data I/O pads, the data transmission circuit including:

first transmitters, each configured to transmit a respective one of the first data signals to the semiconductor memory device; and

second transmitters, each configured to transmit a respective one of the second data signals to the semiconductor memory device.

16. The electronic device of claim 15 , wherein:

each of the first receivers includes:

a comparator configured to compare a respective one of the first data signals with the first reference voltage to output a comparison signal and configured to adjust the duty of the respective one of the first data signals in response to the reception control code set; and

a data sampler configured to sample the comparison signal based on a data strobe signal to output a target data bit.

17. The electronic device of claim 15 , wherein:

the application processor further includes an on-chip memory connected to the training circuit,

the training circuit is configured to:

calculate eye opening values of an initial value through a final value of possible combinations of the reception control code set by sweeping the possible combinations from the initial value to the final value; and

store the eye opening values in the on-chip memory with a table form, and

the memory controller is configured to use a control code associated with an eye opening value having a maximum value among the eye opening values in a normal read operation with the semiconductor memory device.

18. The electronic device of claim 15 , wherein:

the application processor further includes an on-chip memory connected to the training circuit,

the training circuit is configured to:

generate eye opening values of an initial value through a final value of possible combinations of a transmission control code set by sweeping the possible combinations from the initial value to the final value; and

store the eye opening values in the on-chip memory with a table form, and

the memory controller is configured to use a control code associated with an eye opening value having a maximum value among the eye opening values in a normal write operation with the semiconductor memory device.

19. The electronic device of claim 13 , wherein the semiconductor memory device includes a dynamic random access memory (DRAM) device including a plurality of volatile memory cells coupled to a plurality of word-lines and a plurality of bit-lines.

20. An application processor comprising:

a memory interface connected to a semiconductor memory device through first data input/output (I/O) pads and second data I/O pads;

a memory controller configured to exchange data with the semiconductor memory device by controlling the memory interface; and

an on-chip memory connected to the memory interface, wherein:

the memory interface includes a training circuit configured to perform duty training of first data signals and second data signals, based on a reception control code set, by:

adjusting a duty of each of the first data signals with respect to a first reference voltage, the first data signals received through the first data I/O pads; and

adjusting a duty of each of the second data signals with respect to a second reference voltage, the second data signals received through the second data I/O pads,

the memory interface includes:

a data reception circuit connected to the first data I/O pads and the second data I/O pads, the data reception circuit including:

first receivers, each configured to receive a respective one of the first data signals from the semiconductor memory device; and

second receivers, each configured to receive a respective one of the second data signals from the semiconductor memory device; and

a data transmission circuit connected to the first data I/O pads and the second data I/O pads, the data transmission circuit including:

first transmitters, each configured to transmit a respective one of the first data signals to the semiconductor memory device; and

second transmitters, each configured to transmit a respective one of the second data signals to the semiconductor memory device, and

the training circuit is configured to:

calculate eye opening values of an initial value through a final value of possible combinations of the reception control code set by sweeping the possible combinations from the initial value to the final value; and

store the eye opening values in the on-chip memory with a table form.