Method of calibrating signal skews in MIPI and related transmission system
In calibration mode, a clock signal and a data signal are respectively transmitted via a clock lane and a data lane of an MIPI. A test clock signal is provided by adjusting the phase of the clock signal, and a test data signal is provided by adjusting the phase of the data signal. By latching the test data signal according to the test clock signal, a latched data may be acquired for determining an optimized phase relationship corresponding to the clock lane and the data lane. When transmitting the clock signal and the data signal in normal mode, the signal delays of the clock lane and the data lane may be adjusted according to the optimized phase relationship.
1. A method for calibrating signal skew in an MIPI (mobile industry processor interface), comprising:
transmitting a clock signal via a clock lane of the MIPI and transmitting a first data signal via a data lane of the MIPI in a calibration mode;
providing 1 st to N th test clock signals by delaying the clock signal by 0 to (N−1) units of time, wherein N is an integer larger than 1;
providing 1 st to N th first test data signals by delaying the first data signal by 0 to (N−1) units of time;
acquiring 2N first latched data by latching the 1 st to N th first test data signals according to the 1 st test clock signal and by latching the 1 st first test data signal according to the 1 st to N th test clock signals, respectively;
determining whether each first latched data matches first predetermined data associated with the first data signal;
determining a first data pass zone which matches the first predetermined data;
acquiring an optimized phase relationship between the clock lane and the data lane according to a center of the first data pass zone; and
adjusting a signal delay of the clock lane and a signal delay of the data lane according to the optimized phase relationship when transmitting the clock signal and the first data signal in a normal mode.
2. A method for calibrating signal skew in an MIPI (mobile industry processor interface), comprising:
transmitting a clock signal via a clock lane of the MIPI in a calibration mode;
transmitting a first data signal and a second data signal via a data lane of the MIPI in the calibration mode, wherein the first and second data signals have different values;
providing 1 st to N th test clock signals by delaying the clock signal by 0 to (N−1) units of time, wherein N is an integer larger than 1;
providing 1 st to N th first test data signals by delaying the first data signal by 0 to (N−1) units of time;
providing 1 st to N th second test data signals by delaying the second data signal by 0 to (N−1) units of time;
acquiring 2N first latched data by latching the 1 st to N th first test data signals according to the 1 st test clock signal and by latching the 1 st first test data signal according to the 1 st to N th test clock signals, respectively;
acquiring 2N second latched data by latching the 1 st to N th second test data signals according to the 1 st test clock signal and by latching the 1 st second test data signal according to the 1 st to N th test clock signals, respectively;
determining whether each first latched data matches first predetermined data associated with the first data signal;
determining whether each second latched data matches second predetermined data associated with the second data signal;
determining a first data pass zone which matches the first predetermined data;
determining a second data pass zone which matches the second predetermined data;
acquiring an optimized data pass zone of the data channel according to the first data pass zone and the second data pass zone;
acquiring an optimized phase relationship between the clock lane and the data lane according to a center of the optimized data pass zone; and
adjusting a signal delay of the clock lane and a signal delay of the data lane according to the optimized phase relationship when transmitting the clock signal and the first data signal in a normal mode.
3. A transmission system using an MIPI (mobile industry processor interface), comprising:
a host side circuit configured to transmit a clock signal via a first lane of the MIPI and transmit a data signal via a second lane of the MIPI; and
a client side circuit configured to adjust a signal delay of the first lane and a signal delay of the second lane according to an optimized phase relationship, comprising:
a receiving circuit configured to receive the clock signal and the data signal; and
a calibration circuit configured to:
provide 1st to Nth test clock signals by delaying the clock signal by 0 to (N−1) units of time, wherein N is an integer larger than 1;
provide 1st to Nth test data signals by delaying the data signal by 0 to (N−1) units of time;
acquire 2N latched data by latching the 1st to Nth test data signals according to the 1st test clock signal and by latching the 1st test data signal according to the 1st to Nth test clock signals, respectively;
determine whether each latched data matches predetermined data associated with the data signal;
determine a data pass zone which matches the predetermined data; and
acquire the optimized phase relationship between the first lane and the second lane according to a center of the data pass zone.
4. The transmission system of claim 3 ,
wherein the calibration circuit comprises:
a delay unit configured to adjust the phase of the clock signal and the phase of the data signal;
a comparator configured to compare the latched data with the predetermined data associated with the data signal;
a storage unit configured to store a comparing result of the comparator;
a computing unit configured to acquire the optimized phase relationship according to the comparing result; and
a controller configured to control the delay unit according to the optimized phase relationship for adjusting the signal delay of the first lane and the signal delay of the second lane.