JP2011049968A - Device measuring device for mobile terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform measurement in a state corresponding to a power consumption reduction mode of a device for a mobile terminal. <P>SOLUTION: In a term discriminating means 30, the output signal of a waveform shaper 27 is received by a detection circuit 31 and a signal Vx of a DC voltage which is different between a signal present term and a signal absent term, is outputted. During the signal present term, a serial data signal Rd is outputted at a predetermined bit rate from a device 1 for a mobile terminal to be measured, and during the signal absent term, the serial data signal Rd is not outputted. A comparator 32 compares an output signal Vx of the detection circuit 31 with a predetermined threshold Vr for discriminating the signal present term and the signal absent term. While the signal present term is discriminated as being such, a switch 33 is closed to maintain a terminated state by a termination resistor 25 for a signal line; and while the signal absent term is discriminated, the switch 33 is opened to cancel the terminated state by the termination resistor 25. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an apparatus for grasping the operation of a mobile terminal device, and more particularly to a technique for enabling measurement in a state corresponding to a power consumption reduction mode of the mobile terminal device.

  Mobile terminals typified by mobile phones have been increased in speed year by year, and techniques for reducing the increase in power consumption associated therewith are being actively studied.

  Devices used in such portable terminals are increasingly integrated year by year, and at present, a front end unit including a power amplifier and an antenna switching unit and a high-frequency signal modulated by a baseband signal are generated to generate a front end. An RF signal processing unit that demodulates a high-frequency signal received by the front end unit and obtains a baseband signal, and generates a baseband signal including information such as voice and data, and provides the RF signal processing unit The baseband processing unit reproduces voice and data from the baseband signal from the RF signal processing unit, and among these, the RF signal processing unit and the baseband processing unit are becoming dedicated ICs.

  When developing such a terminal device and evaluating its operation, it is necessary to give a test signal to the target device and analyze the signal output from the device in response to the signal.

  The applicant of the present application discloses an example of a terminal device measuring apparatus used for such a purpose in Patent Document 1.

JP 2008-17131 A

  By the way, the baseband signal output from the RF signal processing unit of the portable device is generally a high-speed serial data signal, and this serial data signal is communicated with the database processing unit. The device constituting the unit is designed to have a predetermined output impedance (for example, 50Ω) suitable for high-speed transmission, and the signal is terminated with a resistor equal to the impedance and input to a waveform shaper or the like.

  In addition, a direct-current voltage other than 0 volts is normally output to the baseband output of the RF signal processing unit of the portable terminal device, and high and low data signals are based on the direct-current voltage. Is output.

  Therefore, regardless of the presence or absence of a serial data signal, a DC voltage is steadily applied to the termination resistor to thereby consume power. In recent years, in order to reduce the power consumption of mobile terminals, the power consumed by this termination resistor has also been targeted for reduction. The state in which the termination resistor is turned on (communication period) and the termination resistance Is switched to a state in which communication is not performed (no signal period) in a very short time.

  For this reason, even in the measurement of the mobile terminal device, it is required to perform the measurement in response to such state switching.

  The present invention has been made to meet such demands, and an object of the present invention is to provide a mobile terminal device measurement apparatus that can perform measurement in a state corresponding to the power consumption reduction mode of the mobile terminal device.

In order to achieve the above object, a device measuring apparatus for a portable terminal of the present invention comprises:
A terminating resistor (25, 25A, 25B) for receiving a serial data signal output from the device under test (1) for a portable terminal;
In a mobile terminal device measurement apparatus having a data analysis unit (28) for performing an analysis process on a serial data signal received from the signal line,
Period determining means (30) for determining a signal period during which a serial data signal is output from the device under measurement at a predetermined bit rate and a no-signal period during which the serial data signal is not output;
While the signal determining period is determined by the period determining unit, the termination state by the terminal resistor is held for the signal line, and while the signal determining period is determined by the period determining unit, the signal line is Terminal switching means (33, 33A, 33B) for canceling the terminal state by the terminal resistor is provided.

Moreover, the device measuring apparatus for portable terminals of Claim 2 of this invention is the device measuring apparatus for portable terminals of Claim 1,
A waveform shaper (27) is connected to the end of the signal line, receives the serial data signal output from the signal line, shapes the waveform, and outputs the waveform-shaped serial data signal to the data analysis unit. And
The period determining means includes
A detection circuit (31) that receives an output signal of the waveform shaper and outputs a DC signal having a different voltage in the signal-present period and the no-signal period;
It comprises a comparator (32) that compares the output signal of the detection circuit with a predetermined threshold value and discriminates between the signaled period and the zero signal period.

  As described above, the device measuring apparatus for a portable terminal of the present invention has a signal period during which the serial data signal is output from the device under test for the portable terminal at a predetermined bit rate, and no serial data signal is output. While the signal period is determined, the termination state by the termination resistor for the signal line is maintained while the signal period is determined, and the termination state by the termination resistor for the signal line is maintained while the signal line is determined. Since the cancellation is made, measurement in an operation mode in which useless power consumption of the termination resistor in the non-signal period does not occur can be performed, and measurement of a device under measurement with reduced power consumption becomes possible.

Configuration diagram of an embodiment of the present invention Operation explanatory diagram of the embodiment of the present invention Main part block diagram of another embodiment of this invention Main part block diagram of another embodiment of this invention

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows the overall configuration of a mobile terminal device measuring apparatus 20 to which the present invention is applied.

  In FIG. 1, a test signal generation unit 21 generates a high frequency signal Srf necessary for testing the device under test 1 for a portable terminal, and supplies the high frequency signal Srf to the high frequency signal input port 1 a of the device under measurement 1.

  The device under test 1 includes the RF signal processing unit, which receives power supply (not shown), receives a control signal C required for a test from the control unit 22 at the control signal port 1b, and is inputted. A frequency conversion process for the high-frequency signal Srf and a demodulation process for the baseband serial data signal Rd are performed based on the control signal C. The serial data signal Rd is a high-speed serial data signal called an 8B / 10B frame.

  The output port 1c of the device under test 1 is designed to have a predetermined output impedance (for example, 50Ω) suitable for high-frequency transmission, and is connected to a signal line L having a transmission impedance equal to the output impedance. A terminal resistor 25 having a resistance value equal to the transmission impedance and a waveform shaper 27 are connected to the end of L.

  Therefore, the serial data signal Rd output from the output port 1 c of the device under test 1 is supplied to the termination resistor 25 and the waveform shaper 27 via the signal line L. Note that, as described above, a DC voltage other than 0 volts is constantly output to the output port 1c of the device under test 1, and high and low data signals are output based on the DC voltage. .

  Since the waveform shaper 27 is composed of a high-speed saturated amplifier or the like and has a high input impedance with respect to the transmission impedance, a termination resistor 25 is provided to suppress the generation of reflection components due to the mismatch. It has been.

  However, the other end of the termination resistor 25 is grounded via a switch 33 described later, and the termination is valid when the switch 33 is closed, and the termination is invalid when the switch 33 is open. .

  The serial data signal Rd ′ waveform-shaped by the waveform shaper 27 is input to the data analysis unit 28, and undergoes, for example, clock recovery processing, parallel data conversion processing (DEMUX), etc., and analysis processing (for example, signal processing) necessary for performance evaluation. Analysis, bit error checking, etc.).

  The serial data signal Rd ′ waveform-shaped by the waveform shaper 27 is input to the period determining means 30.

  The period determining means 30 discriminates between a signal period Ton in which the serial data signal Rd is continuously output from the device under test 1 at a predetermined bit rate and a no-signal period Toff in which the serial data signal Rd is not output. To do.

  Various configurations of the period determination means 30 are conceivable. In this embodiment, in order to prevent a processing delay for a high-speed serial data signal, the serial data signal Rd ′ output from the waveform shaper 27 is received. A detection circuit 31 that performs diode detection, smooths the output thereof (or detects a DC average value by a resistor or a coil), and outputs a DC signal having a different voltage in the signal period Ton and the no-signal period Toff; Comparing the output signal Vx of the detection circuit 31 with a predetermined threshold value Vr set in advance, the comparator 32 is composed of a high-speed comparator that determines the signaled period Ton and the no-signal period Toff. . The detection circuit 31 may be either a DC average value output type or a peak value output type.

  The output Vc of the comparator 32 is input to the switch 33 as termination switching means of this embodiment. The switch 33 is composed of, for example, a high-speed analog switch, and is closed while the period determining unit 30 determines that the signal period is Ton (Vc is a high level period), and the other end of the termination resistor 25 is grounded. The termination state by the termination resistor 25 for the signal line L is held.

  Further, while the period determining means 30 determines that the no-signal period is off (Vc is a low level period), the terminal is disconnected between the other end of the termination resistor 25 and the ground, and the signal line L is disconnected. The termination state by the termination resistor 25 is canceled.

  FIG. 2 shows an example of the operation of the mobile terminal device measuring apparatus 20 having the above-described configuration. For example, an 8B / 10B frame serial data signal Rd as shown in FIG. In this case, until the end of transmission of data at the end of the frame called EOT (End of Transmission) is completed, the mark rate ½ is generated with almost the same probability, so that the detection circuit If the output signal Vx 31 is a DC average value output type, the output signal Vx is approximately an intermediate value V () between the data high level voltage V (H) and low level voltage V (L) as shown in FIG. M).

  Here, the threshold value Vr is set between the intermediate value V (M) and the low level voltage V (L). Therefore, during this time, the output Vc of the comparator 32 is maintained at a high level as shown in FIG. 2C, the switch 33 is kept closed, and the termination state of the signal line L by the termination resistor 25 continues.

  Since the period from the end of the output of the data at the end of the frame to the input of the start signal of the next frame (referred to as a stall period) is in a no-signal state, the output signal Vx of the detection circuit 31 is It becomes equal to the low level voltage V (L).

  Therefore, the output Vc of the comparator 32 immediately changes to the low level, the switch 33 is opened, and the termination state by the termination resistor 25 for the signal line L is released.

  In this state, no power is consumed by the termination resistor 25, and the device under measurement 1 is in the power consumption reduction mode.

  Then, when the head signal of the next frame (for example, a signal with “1” called “prepare” continuing) is input, the output signal Vx of the detection circuit 31 becomes equal to the high level voltage V (H), and therefore the comparator 32. The output Vc immediately changes to the high level, the switch 33 is closed, and the terminal line 25 returns to the termination state with respect to the signal line L.

  Thereafter, while the data signal following the prepare is input, the output signal Vx of the detection circuit 31 is at the intermediate value V (M), so that the termination state by the termination resistor 25 is held.

  Thus, according to the embodiment of the present invention, it is possible to simulate an operation mode in which useless power consumption of the termination resistor 25 in the no-signal period Toff does not occur, and the mobile terminal device that operates in the low power consumption mode. Measurement is possible.

In the above embodiment, the output of the device under test 1 and the waveform shaper 27 are single-ended for easy explanation. However, when configuring an actual measurement apparatus, the difference for the high-speed interface is used. LVDS (Low voltage differential) which is a dynamic I / O standard
signaling), LVPECL (Low Voltage Positive Emitter Coupled)
Logic), PCML (Pseudo Current Mode Logic), etc. are desirable.

  FIG. 3 shows a differential 100Ω termination type corresponding to the LVDS standard, wherein the device under measurement 1 and the waveform shaper 27 are of the differential type, and the serial data signal Rd (+) inverted from the device under measurement 1. , Rd (−) are output to the signal lines L1 and L2 via the output ports 1c and 1c ′, and one end of the terminating resistors 25A and 25B and the waveform shaper 27 are connected to the ends thereof. However, the present invention can be similarly applied.

  In this case, one of the outputs Rd (+) ′ and Rd (−) ′ of the waveform shaper 27 (here, Rd (+) ′) is input to the period determining unit 30, and the period determining unit 30 performs a signaled period. While it is determined as Ton, for example, the switch 33 is closed by a high level output signal Vc, and the other ends of the two termination resistors 25A and 25B are connected to each other, and the signal lines L1 and L2 are terminated at 100Ω.

  Further, while it is determined that there is no signal period Toff, for example, the switch 33 is opened by the low-level output signal Vc, and the other ends of the two termination resistors 25A and 25B are disconnected to release the termination state. In this case, there is no power consumption by the termination resistors 25A and 25B, and the mobile terminal device 1 is in the power consumption reduction mode.

  Further, by using the detection wave circuit 31 described above, the comparator 32 using a high-speed comparator, and the switch 33 using a high-speed analog switch, switching from an actual signal period to a no-signal period or from a signal-free period to a signal period It has been confirmed that the termination state can be released and restored within a delay time of 4 to 5 ns with respect to switching to, and high speed enough to cope with the no-signal period between high-speed 8B / 10B frames is obtained. ing.

  Here, the 100Ω termination is realized by connecting two termination resistors 25A and 25B in series, but a single 100Ω termination resistor may be connected between the signal lines L1 and L2 by a switch.

  FIG. 4 shows a single 50Ω termination type corresponding to the LVPECL and PCML standards. One end of each of the 50Ω termination resistors 25A and 25B is connected to the ends of the signal lines L1 and L2, and the other end side is connected to each other. The switch is connected to a predetermined terminal potential Vs according to the standard via the switches 33A and 33B.

  Even in this configuration, as described above, one of the outputs Rd (+) ′ and Rd (−) ′ of the waveform shaper 27 (here, Rd (+) ′) is input to the period discriminating means 30 and the period While it is determined by the determination means 30 that the signal period is Ton, for example, the switches 33A and 33B are closed by the high level output signal Vc, and the other ends of the two termination resistors 25A and 25B are connected to the termination potential Vs. Keep state.

  Further, while it is determined that there is no signal period Toff, for example, the switches 33A and 33B are opened by the low level output signal Vc, and the other end of the two termination resistors 25A and 25B is disconnected from the termination potential Vs to cancel the termination state. To do.

  In the above embodiment, the output signal of the waveform shaper 27 is input to the period determining unit 30 to determine the no-signal period and the signaled period. However, the signal input to the waveform shaper 27 is determined to be the period determining unit. It is also possible to discriminate between a no-signal period and a signal-present period by inputting to 30.

  DESCRIPTION OF SYMBOLS 1 ... Device to be measured, 20 ... Device measuring device for portable terminal, 21 ... Test signal generation unit, 22 ... Control unit, 25, 25A, 25B ... Termination resistor, 27 ... Waveform shaper, 28 ... ... Data analysis section, 30 ... Period determination means, 31 ... Detection circuit, 32 ... Comparator, 33, 33A, 33B ... Switch

Claims (2)

A terminating resistor (25, 25A, 25B) for terminating the signal line for receiving the serial data signal output from the device under test (1) for the portable terminal;
In a mobile terminal device measurement apparatus having a data analysis unit (28) for performing an analysis process on a serial data signal received from the signal line,
Period determining means (30) for determining a signal period during which a serial data signal is output from the device under measurement at a predetermined bit rate and a no-signal period during which the serial data signal is not output;
While the signal determining period is determined by the period determining unit, the termination state by the terminal resistor is held for the signal line, and while the signal determining period is determined by the period determining unit, the signal line is A terminal measuring device (33, 33A, 33B) for canceling the termination state due to the termination resistor is provided. A waveform shaper (27) is connected to the end of the signal line, receives the serial data signal output from the signal line, shapes the waveform, and outputs the waveform-shaped serial data signal to the data analysis unit. And
The period determining means includes
A detection circuit (31) that receives an output signal of the waveform shaper and outputs a DC signal having a different voltage in the signal-present period and the no-signal period;
The comparator (32) which compares the output signal of the said detection circuit with a predetermined threshold value, and discriminate | determines the said signal period and the said no signal period, It is comprised. Device measuring device for mobile terminals.

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