Semiconductor device, adjustment method thereof and data processing system
A method includes resetting an output timing adjustment circuit in each of a plurality of DRAM devices to a default output timing data value, measuring a default delay from read command to read data for each of the plurality of DRAM devices, identifying a slowest DRAM device having a maximum default delay from read command to read data among the plurality of DRAM devices, writing an output timing data value to the output timing adjustment circuit in each of the plurality of DRAM devices to set the delay from read command to read data for each respective DRAM device to an amount substantially equal to the maximum default delay, and reading data from any one of the plurality of DRAM devices with a delay from read command to read data substantially equal to the maximum default delay.
1. A method, comprising:
resetting an output timing adjustment circuit in each of a plurality of DRAM devices to a default output timing data value, the plurality of DRAM devices being provided in a stacked configuration and connected by through silicon vias;
measuring a default delay from read command to read data for each of the plurality of DRAM devices;
identifying a slowest DRAM device having a maximum default delay from read command to read data among the plurality of DRAM devices;
writing an output timing data value to the output timing adjustment circuit in each of the plurality of DRAM devices to set the delay from read command to read data for each respective DRAM device to an amount substantially equal to the maximum default delay; and
reading data from any one of the plurality of DRAM devices with a delay from read command to read data substantially equal to the maximum default delay.
2. The method as claimed in claim 1 , wherein the measuring the default delay comprises inputting a replica circuit input signal to a replica circuit within each respective DRAM device, the replica circuit input signal having a delay substantially the same as that of control logic circuits and data control circuits within each respective DRAM device.
3. The method as claimed in claim 2 , wherein the replica circuit comprises a test through silicon via.
4. The method as claimed in claim 1 , wherein measuring the default delay comprises carrying out a repeated operation.
5. The method as claimed in claim 4 , wherein the repeated operation comprises comparing the default delay from read command to read data for each of the plurality of DRAM devices to a delay of the variable delay circuit and adjusting the delay of the variable delay circuit until the default delay from read command to read data for each of the plurality of DRAM devices and the delay of the variable delay circuit are substantially equal.
6. The method as claimed in claim 5 , wherein the variable delay circuit is included in an interface chip connected to the plurality of DRAM devices.
7. The method as claimed in claim 1 , further comprising calculating a difference between the maximum default delay and the default delay from read command to read data for each of the plurality of DRAM devices.
8. The method as claimed in claim 1 , wherein the plurality of DRAM devices are synchronous DRAM devices.
9. The method as claimed in claim 1 , wherein the plurality of DRAM devices are double data rate synchronous DRAM devices.
10. A method, comprising:
resetting an output timing adjustment circuit in each of a plurality of DRAM devices to a default output timing data value, the plurality of DRAM devices being provided, along with an interface chip, in a stacked configuration and connected by through silicon vias;
measuring a default delay from read command to read data for each of the plurality of DRAM devices;
identifying a slowest DRAM device having a maximum default delay from read command to read data among the plurality of DRAM devices;
writing an output timing data value to the output timing adjustment circuit in each of the plurality of DRAM devices to set the delay from read command to read data for each respective DRAM device to an amount substantially equal to the maximum default delay; and
reading data from any one of the plurality of DRAM devices with a delay from read command to read data substantially equal to the maximum default delay,
wherein at least the measuring, the identifying and the writing are performed by the interface chip.
11. The method as claimed in claim 10 , wherein the interface chip comprises an input timing adjustment circuit to set the delay an input timing signal.
12. The method as claimed in claim 11 , wherein the input timing adjustment circuit is set to a delay to allow the input timing signal to capture read data from each of the plurality of DRAM devices.
13. The method as claimed in claim 12 , wherein the input timing adjustment circuit is set to the maximum default delay.
14. The method as claimed in claim 10 , wherein the plurality of DRAM devices are synchronous DRAM devices.
15. The method as claimed in claim 10 , wherein the plurality of DRAM devices are double data rate synchronous DRAM devices.