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Mobile Phone Patent Abstract
A mobile phone has at least one main clock system and operating
based on a main clock signal of the main clock system. The main
clock system includes a main counter for counting main clocks of
the main clock signal; and a power saving section for stopping generation
of the main clock signal for a time period, while counting wait
clocks of a wait clock signal, for restarting the generation of
the main clock signal after the time period, and for controlling
the main counter the main counter based on the counted wait clocks
as if the main counter always counts the main clocks of the main
clock signal.
Mobile Phone Patent Claims
What is claimed is:
1. A mobile phone having at least one main clock system and operating
based on a main clock signal of said main clock system, wherein
said main clock system comprising: a main counter configured to
count main clocks of said main clock signal; and a power saving
circuit configured to stop generation of said main clock signal
for a time period, while counting wait clocks of a wait clock signal,
to restart the generation of said main clock signal after the time
period, and to control said main counter based on the counted wait
clocks as if said main counter always counts said main clocks of
said main clock signal, wherein said power saving circuit comprises:
a correction controller configured to count said wait clocks of
said wait clock signal for the time period during which the generation
of said main clock signal is stopped, and to correct a count value
of said main counter based on the counted wait clocks, said correction
controller comprises: a single counter configured to count said
wait clocks of said wait clock signal for the time period during
which the generation of said main clock signal is stopped; and a
calculator configured to calculate said main clocks while the generation
of said main clock signal is stopped; and a setting circuit configured
to correct the count value of said main counter based on the calculated
main clocks.
2. The mobile phone according to claim 1, wherein said power saving
circuit further comprises: a stop controller configured to stop
the generation of said main clock signal; and a restart controller
configured to restart the generation of said main clock signal after
said time period elapses, such that said main counter counts said
main clocks from the corrected count value.
3. The mobile phone according to claim 1, wherein a frequency of
said main clock signal is larger than a frequency of said wait clock
signal.
4. The mobile phone according to claim 1, wherein the time period
during which the generation of said main clock signal is stopped
is predetermined.
5. The mobile phone according to claim 1, wherein said calculator
comprises: a ratio calculator configured to determine a frequency
ratio of a frequency of said main clock signal to a frequency of
said wait clock signal; a CPU reading out a count value from said
main counter when the generation of said main clock signal is stopped,
and calculating said main clocks while the generation of said main
clock signal is stopped, based on the counted wait clocks of said
wait clock signal.
6. The mobile phone according to claim 5, further comprising: a
battery; and said ratio calculator calculates when a voltage of
said battery changes.
7. The mobile phone according to claim 5, further comprising: a
temperature sensor; and said ratio calculator calculates when said
temperature sensor senses change of a temperature of said mobile
phone.
8. The mobile phone according to claim 1 comprising first and second
main clock systems, each of which is same as said main clock system.
9. The mobile phone according to claim 8, wherein said wait clock
signal is shared by said first and second main clock systems.
10. A mobile phone having at least one main clock system, said
main clock system comprising: a main clock generator which generates
a main clock signal; a single main counter which carries out a counting
operation of main clock of said main clock signal in response to
said main clock signal generated by said main clock generator; and
a processor which stops the counting operation of said main counter
by stopping the generation of said main clock by said main clock
generator before entering a waiting operation and changes a count
value of said main counter as if the counting operation of said
main counter has been not stopped when going out of the waiting
operation, said change is based upon a preset value include a ratio
of the frequency of the main clock signal to the frequency of the
wait clock signal. wherein said processor comprises: a wait timer
which carries out a counting operation of wait clocks of a wait
clock signal in response to a wait clock signal for a predetermined
time corresponding to a time period during which the generation
of said main clock signal is stopped; and a CPU which operates based
on the count value of said main counter in response to said main
clock signal, said CPU changes the count value of said main counter
by adding data corresponding to the number of said main clocks while
the counting operation of said main counter is stopped, to the count
value of said main counter, said CPU calculates said data to be
added, based on said wait clocks counted by said wait timer during
said predetermined time, said processor further comprises: a clock
precision unit which holds a ratio of a frequency of said main clock
signal to a frequency of said wait clock signal, and said CPU calculates
said data by multiplying said wait clocks counted by said wait timer
by said ratio held by said clock precision measuring unit.
11. A method of saving power consumption in a mobile phone having
at least one main clock system and operating based on a main clock
signal of said main clock system, wherein said method comprising;
(a) counting main clocks of said main clock signal using a first
single counting means; (b) stopping generation of said main clock
signal for a time period, while counting wait clocks of a wait clock
signal using a second single counting means; (c) restarting the
generation of said main clock signal after the time period; and
(d) restarting the counting operation of said main clock of said
main clock signal from preset data corresponding to said counted
wait clocks of said wait clock signal, said preset data includes
a ratio of the frequency of the main clock signal to the frequency
of the wait clock signal, wherein said (b) restarting comprises:
(e) counting said wait clocks of said wait clock signal for the
time period; (f) calculating said preset data based on a count value
of said main counter based on said counted wait clocks of said wait
clock signal; and (g) setting said preset data, said (f) calculating
comprises (h) determining the frequency ratio of a frequency of
said main clock signal to a frequency of said wait clock signal;
(i) multiplying said counted wait clocks of said wait clock signal
by said frequency ratio; and (j) adding the counted main clocks
when the generation of said main clock signal is stopped, to the
multiplying result.
12. The method according to claim 11, further comprising carrying
said (h) determining when a voltage of a battery changes.
13. The method according to claim 11, further comprising carrying
said (h) determining when a temperature of said mobile phone changes.
14. A mobile phone having at least one main clock system and operating
based on a main clock signal of said main clock system, wherein
said main clock system comprising: a main counter configured to
count main clocks of said main clock signal; a wait counter configured
to count wait clocks of wait clock signal; a precision measuring
unit configured to calculate said frequency of ratio between said
main clock signal and said wait clock signal; and a controller configured
to stop and restart said generation of said main clock signal, and
to reload a value to said main counter prior to restarting said
generation of said main clock signal, wherein said value is calculated
according to both the time period which said generation of said
main clock is stopped and said frequency ratio between said main
clock signal and said wait clock signal.
15. The mobile phone claimed in claim 14, further comprising: a
temperature sensor, wherein said precision measuring unit calculates
said frequency ratio between said main clock signal and said wait
clock signal when temperature sensor detects temperature change.
16. The mobile phone claimed in claim 14, further comprising: a
battery, wherein said precision measuring unit calculates said frequency
ratio between said main clock signal and said wait clock signal
when said battery detects the voltage change.
17. The mobile phone according to claim 14, wherein a frequency
of said main clock signal is larger than a frequency of said wait
clock signal.
18. The mobile phone according to claim 14, wherein the time period
which the generation of said main clock signal is stopped is variable.
19. The mobile phone according to claim 14 comprising first and
second main clock systems each of which is same as said main clock
system.
20. A mobile phone according to claim 19, wherein said wait clock
signal is shared by said first and second main clock systems.
Mobile Phone Patent Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a mobile phone, and more particularly
to a technique which suppresses power consumption in a waiting operation
of a mobile phone.
2. Description of the Related Art
Conventionally, a mobile phone has been come into a practical use.
In the mobile phone, a waiting operation peculiar to the mobile
phone is carried out in addition to a usual operation such as speech
communication and data communication. A substantial function of
the mobile phone is not realized during the waiting operation. Therefore,
a control is carried out during the waiting operation to prevent
power consumption of a battery.
A control unit used in a conventional mobile phone will be described
with reference to FIG. 1. The conventional control unit is composed
of a central processing unit (CPU) 10, a main clock generator 11,
a wait clock generator 12, a wait timer 13 and a main counter 14.
The main clock generator 11 generates a main clock signal to operate
the control unit and supplies to the CPU 10 and the main counter
14. The CPU 10 operates in response to the main clock signal to
control the whole control unit of the mobile phone. The main counter
14 carries out a counting operation in response to the main clock.
The CPU 10 controls communication between a base station and the
mobile phone in accordance with the count value of the main counter
14.
The wait clock generator 12 generates a wait clock signal and supplies
to the wait timer 13. The wait timer 13 operates in response to
the wait clock. The wait timer 13 generates a start signal and supplies
to the main clock generator 11. Also, the wait timer 13 generates
an interruption signal and supplies to the CPU 10. Thus, the wait
timer 13 controls an operation before and after a waiting operation.
In the above configuration, the operation of the control unit of
the conventional mobile phone will be described. The CPU 10 specifies
a wait time before entering the waiting operation, and then issues
a main clock stop instruction to the main clock generator 11. Also,
the CPU 10 issues a wait timer start instruction to the wait timer
13. By this, the main clock generator 11 stops the generation of
the main clock signal. As a result, the CPU 10 enters a sleep mode
and the counting operation of the main counter 14 is stopped.
When the specified wait time elapses in the sleep mode, the wait
timer 13 supplies a start signal to the main clock generator 11
to restarts the main clock generator 11 and supplies an interruption
signal to the CPU 10 to restart the operation of the CPU 10. Thus,
the counting operation of the main counter 14 is restarted and the
CPU 10 can communicate with a base station in accordance with the
count value of the main counter 14. The power consumption of a battery
can be suppressed because the main clock signal is stopped in the
waiting operation through above operation. However, the count value
of the main counter becomes discrete before and after the waiting
operation.
By the way, in the frequency division multiple access (FDMA) and
the time division multiple access (TDMA) which are adopted in the
conventional mobile phone, because the status of the CPU can be
generally changed from the waiting operation in accordance with
the reception of electric wave from the base station, there is not
a problem, even if the count value of the main counter become discrete.
Also, in the mobile phone of the code division multiple access
(CDMA) system, continuity of the count value of the main counter
before and after the waiting operation is required. However, the
main clock signal is low in frequency and is near the frequency
of the wait clock signal. For this reason, it is possible to correct
the count value of the main counter by searching for a few clocks
to maintain the continuity of the count value of the main counter.
However, in the wide band--code division multiple access (W-CDMA),
because the frequency of a main clock signal is high considerably,
compared with the frequency of the wait clock. For this reason,
it is impossible to correct the count value of the main counter
to maintain the continuity of the count value before and after the
waiting operation. Moreover, in the W-CDMA system, it is not possible
to carry out communication if the count value of the main counter
is shifted by one clock. Therefore, in the W-CDMA system, it is
necessary that the main clock signal is not stopped even during
the wait operation or the communication synchronization with the
base station is established again after the wait operation.
If it is supposed that the main clock signal is not stopped during
the wait operation, the power consumption during the wait operation
becomes larger tens of times, compared with the case where the main
clock signal is stopped. Also, if it is supposed that the communication
synchronization is established again after the wait operation, a
process time after the wait operation becomes 10 times or more,
resulting in increase of the power consumption.
SUMMARY OF THE INVENTION
Therefore, an object of the present invention is to provide a mobile
phone in which the power consumption can be suppressed.
Another object of the present invention is to provide a mobile
phone in which a main clock signal can be stopped during a waiting
operation.
Still another object of the present invention is to provide a mobile
phone in which a process time after a waiting operation can be decreased.
In an aspect of the present invention, a mobile phone has at least
one main clock system and operating based on a main clock signal
of the main clock system. The main clock system includes a main
counter for counting main clocks of the main clock signal; and a
power saving section for stopping generation of the main clock signal
for a time period, while counting wait clocks of a wait clock signal,
for restarting the generation of the main clock signal after the
time period, and for controlling the main counter the main counter
based on the counted wait clocks as if the main counter always counts
the main clocks of the main clock signal.
Here, the power saving section may include a stop control section,
a correction control section and a restart control section. The
stop control section stops the generation of the main clock signal.
The correction control section counts the wait clocks of the wait
clock signal for the time period during which the generation of
the main clock signal is stopped, and corrects a count value of
the main counter based on the counted wait clocks. The restart control
section restarts the generation of the main clock signal after the
time period elapses, such that the main counter counts the main
clocks from the corrected count value.
Also, it is desirable that the frequency of the main clock signal
is larger than a frequency of the wait clock signal.
Also, the time period during which the generation of the main clock
signal is stopped is desirably predetermined.
Also, the correction control section may include a counting section
for counting the wait clocks of the wait clock signal for the time
period during which the generation of the main clock signal is stopped;
a calculating section for calculating the main clocks while the
generation of the main clock signal is stopped; and a setting section
for correcting the count value of the main counter based on the
calculated main clocks. In this case, the calculating section may
include a ratio section, a read section and another section. The
ratio section determines a frequency ratio of a frequency of the
main clock signal to a frequency of the wait clock signal. The read
section reads out a count value from the main counter when the generation
of the main clock signal is stopped. The other section calculates
the main clocks while the generation of the main clock signal is
stopped, based on the counted wait clocks of the wait clock signal.
At this time, the mobile phone may further include a battery; and
a first driving section for driving the ratio section when a voltage
of the battery changes. Otherwise, the mobile phone may further
include a temperature sensor; and a second driving section for driving
the ratio section when the temperature sensor senses change of a
temperature of the mobile phone.
Also, the mobile phone may include first and second main clock
systems, each of which is configured as mentioned above. In this
case, the wait clock signal is shared by the first and second main
clock systems.
In another aspect of the present invention, a mobile phone has
at least one main clock system. The main clock system includes a
main clock generator which generates a main clock signal; a main
counter which carries out a counting operation of main clock of
the main clock signal in response to the main clock signal generated
by the main clock generator; and a processor which stops the counting
operation of the main counter by stopping the generation of the
main clock by the main clock generator before entering a waiting
operation and changes a count value of the main counter as if the
counting operation of the main counter has been not stopped when
going out of the waiting operation.
Here, the processor may include a wait timer which carries out
a counting operation of wait clocks of a wait clock signal in response
to a wait clock signal for a predetermined time corresponding to
a time period during which the generation of the main clock signal
is stopped; and a CPU which operates based on the count value of
the main counter in response to the main clock signal. In this case,
the wait timer may stop the operations of the main counter and the
CPU by stopping the generation of the main clock signal by the main
clock generator in response to an instruction from the CPU. Also,
the wait timer may control the main clock generator to restart the
generation of the main clock signal and the CPU to change a count
value of the main counter, after the predetermined time elapses.
Also, the CPU may change the count value of the main counter by
adding data corresponding to the number of the main clocks while
the counting operation of the main counter is stopped, to the count
value of the main counter. In this case, the CPU may calculate the
data to be added, based on the wait clocks counted by the wait timer
during the predetermined time. Also, the processor may further include
a clock precision unit which holds a ratio of a frequency of the
main clock signal to a frequency of the wait clock signal. The CPU
calculates the data by multiplying the wait clocks counted by the
wait timer by the ratio held by the clock precision measuring unit.
Also, it is desirable that the predetermined time is set in the
wait timer by the CPU before the wait timer stops the generation
of the main clock signal by the main clock generator.
In still another aspect of the present invention, a mobile phone
has two main clock systems, each of which include a main clock generator
which generates a main clock signal; a main counter which carries
out a counting operation of main clock of the main clock signal
in response to the main clock signal generated by the main clock
generator; and a processor which stops the counting operation of
the main counter by stopping the generation of the main clock by
the main clock generator before entering a waiting operation and
changes a count value of the main counter as if the counting operation
of the main counter has been not stopped when going out of the waiting
operation.
Here, the processor may include a wait timer which carries out
a counting operation of wait clocks of a wait clock signal in response
to a wait clock signal for a predetermined time corresponding to
a time period during which the generation of the main clock signal
is stopped; and a CPU which operates based on the count value of
the main counter in response to the main clock signal.
Also, the wait timer may be shared by the two main clock systems.
In yet still another aspect of the present invention, a method
of saving power consumption in a mobile phone having at least one
main clock system and operating based on a main clock signal of
the main clock system, is attained by (a) counting main clocks of
the main clock signal; by (b) stopping generation of the main clock
signal for a time period, while counting wait clocks of a wait clock
signal; by (c) restarting the generation of the main clock signal
after the time period; and by (d) restarting the counting operation
of the main clock of the main clock signal from preset data corresponding
to the counted wait clocks of the wait clock signal.
The step (b) may be attained by (e) counting the wait clocks of
the wait clock signal for the time period; by (f) calculating the
preset data based on a count value of the main counter based on
the counted wait clocks of the wait clock signal; and by (g) setting
the preset data.
Also, the frequency of the main clock signal is desirably larger
than the frequency of the wait clock signal, and the time period
is desirably predetermined.
Also, the step (f) may be attained by (h) determining a frequency
ratio of a frequency of the main clock signal to a frequency of
the wait clock signal; by multiplying the counted wait clocks of
the wait clock signal by the frequency ratio; and by adding the
counted main clocks when the generation of the main clock signal
is stopped, to the multiplying result. In this case, the method
may further include the step of: carrying the step (h) when a voltage
of a battery changes, or carrying the step (h) when a temperature
of the mobile phone changes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the circuit structure of a conventional
mobile phone;
FIG. 2 is a block diagram showing the circuit structure of a mobile
phone according to a first embodiment of the present invention;
FIG. 3 is a flow chart to show the operation of the mobile phone
in the first embodiment of the present invention;
FIG. 4 is a diagram showing waveforms during the operation of the
mobile phone in the first embodiment of the present invention; and
FIG. 5 is a block diagram showing the circuit structure of the
mobile phone according to a second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, a mobile phone of the present invention will be described
in detail with reference to the drawings.
FIG. 2 is a block diagram showing the circuit structure of the
mobile phone according to the first embodiment of the present invention.
The mobile phone is comprised of a CPU 10, a main clock generator
11, a wait clock generator 12, a wait timer 13, a main counter 14
and a clock signal precision measuring unit 15. A CPU bus 20 connects
the CPU 10, the main clock generator 11, the wait timer 13, the
main counter 14 and the clock signal precision measuring unit 15
mutually.
The CPU 10 controls the whole of the mobile phone. The processing
carried out by the CPU 10 is described in detail later.
The main clock generator 11 generates a main clock signal to enable
the whole operation of the mobile phone. The generation of the main
clock signal is controlled based on a start signal outputted from
the wait timer 13. The main clock signal generated by the main clock
generator 11 is supplied to the CPU 10, the main counter 14 and
the clock signal precision measuring unit 15. The main clock signal
is a rectangular wave signal whose frequency is about 4 MHz, as
shown in FIG. 4A. The main clock signal is kept a low level in a
portion of the waveform shown in FIG. 4A, and the time interval
in the low level is called a wait state in which the main clock
signal is stopped and a waiting operation is carried out in the
mobile phone.
The wait clock generator 12 generates a wait clock signal to control
the waiting operation. The wait clock signal is called a real time
clock signal, and is a rectangular wave signal whose frequency is
about 32 KHz as shown in FIG. 3(B). Unlike the main clock signal,
the wait clock signal is never stopped, and is always generated.
The wait clock signal generated by the wait clock generator 12 is
supplied to the wait timer 13 and the clock signal precision measuring
unit 15.
The wait timer 13 operates based on the wait clock signal from
the wait clock generator 12. The wait timer 13 generates the start
signal when the time specified by the CPU 10 elapses. The wait timer
13 supplies the start signal to the CPU 10 and the main clock generator
11. The start signal is used to start the generation of the main
clock signal by the main clock generator 11.
Also, the wait timer 13 generates and supplies a control signal
to the main counter 14. The control signal is set to the low level
when the wait timer 13 receives a wait timer start instruction from
the CPU 10 and is set to a high level when the count of the wait
timer 13 reaches a full value.
When the control signal is set to the low level, the main counter
14 becomes a hold state and stops the counting operation. In the
hold state, it is possible to set a new count value to the main
counter 14. Also, the main counter 14 restarts the counting operation
from the set count value when the control signal is set to the high
level.
Thus, the main counter 14 is used to manage the whole timings from
the beginning of the communication to the end. The CPU 10 communicates
with the base stations in accordance with the count value of the
main counter 14. Although the main counter 14 sometimes is stopped
as described later, the mobile phone is controlled in such a manner
that the base station can recognize the main counter 14 being always
operating.
The clock signal precision measuring unit 15 calculates the ratio
RATIO of the frequency of the main clock signal from the main clock
generator 11 to the frequency of the wait clock signal from the
wait clock generator 12. The ratio RATIO calculated by the clock
signal precision measuring unit 15 is sent to the CPU 10 through
the CPU bus 20.
Next, the operation of the mobile phone configured as mentioned
above will be described with reference to FIGS. 3 and 4. It should
be noted that the change from an ordinary operation to the waiting
operation in the sleep mode and the restart operation going out
from the waiting operation to the waiting operation will be described
mainly.
The CPU 10 issues the wait timer start instruction to the wait
timer 13 as shown at Step S10 of FIG. 3 when the CPU 10 enters the
waiting operation. The wait timer start instruction is issued in
a suitable timing before entering the waiting operation, as shown
in the timing P2 of FIG. 4C. Also, the CPU 10 sends to the wait
timer 13, data defining a time until the main clock signal is restarted,
simultaneously with the issuance of the wait timer start instruction.
The data is composed of the number WV of clocks of the wait clock
signal.
The wait timer 13 is started in response to the issuance of the
wait timer start instruction, as shown at Step S20 of FIG. 3. That
is, as shown in FIG. 4D, when receiving the wait timer start instruction,
the wait timer 13 starts the counting operation from the wait clock
of the wait clock signal arriving after the timing P3 of FIG. 4C.
At the same time, the wait timer 13 sets the control signal to the
low level, as shown in FIG. 4F. Thus, the main counter 14 enters
the HOLD state, as shown at Step S30 of FIG. 3. That is, the main
counter 14 stops the counting operation, as shown in FIG. 4G, and
holds the count value at the point.
After that, the wait timer 13 generates and supplies a sleep signal
(not shown) to the CPU 10 and the main clock generator 11. Thus,
as shown in FIG. 4A, the main clock signal is stopped (step S21)
and the CPU 10 enters the sleep mode (Step S11).
The wait clocks sent while the main clock signal is stopped after
the issuance of the wait timer start instruction are counted for
the number WV by the wait timer 13. It is preferable that the number
WV of wait clocks includes a loss for the restarting operation.
When counting the wait clocks for the number MW, the wait timer
13 activates the start signal to the high level as shown in FIG.
4E, and sends to the CPU 10 and the main clock generator 11. In
response to the start signal, the main clock generator 11 restarts
the generation of the main clock signal as shown in FIG. 4A (Step
S22). Also, the sleep mode of the CPU 10 is canceled at the timing
P4 shown in FIG. 4 (Step S12). Thus, the CPU 10 restarts operation.
Next, when restarting the operation, the CPU 10 reads the count
value held by the main counter 14 at the timing P5 of FIG. 4C (Step
S13). That is, the main counter 14 sends the count value held at
that time point to the CPU 10 via the CPU bus 20 (Step S31).
Next, the CPU 10 calculates a new counter value RV (Step S14).
The new counter value RV is calculated in accordance with the following
equation: RV=HV+WV.times.RATIO where HV is a count value held by
the main counter 14, WV is the number of wait clocks generated while
the main counter 14 is stopped, and RATIO is the ratio of the frequency
of the main clock signal previously measured by the clock signal
precision measuring unit 15 to the frequency of the wait clock signal.
For example, the calculation of ratio RATIO is carried out at the
timing P1 of FIG. 4. The number of main clocks while the main counter
14 is stopped is calculated from the equation of "WV.times.RATIO".
Next, the CPU 10 sets the calculated new counter value RV to the
main counter 14 at the timing P6 of FIG. 4C (Step S15). Thus, the
new counter value RV is set to the main counter 14 (Step S32).
After that, when the wait timer 13 becomes full, the wait timer
13 sets the control signal to the high level and instructs the main
counter 14 to restart (Step S23). Thus, the counting operation of
the main counter 14 is restarted (Step S33). The count value of
the main counter 14 at this time point is coincident with the count
value which would be counted by the main counter 14 when the generation
of the main clock signal is not stopped. Therefore, the following
process can be is treated as the main clock signal is continuously
outputted and the main counter 14 continues the counting operation.
Because the frequencies of the main clock signal and the wait clock
signal are previously determined, the ratio RATIO of the frequencies
of these clocks should be constant. However, the frequencies of
the main clock signal and the wait clock signal change in accordance
with the temperature and the voltage. It should be noted that the
above mentioned measurement of the ratio RATIO of the frequency
of the main clock signal to the frequency of the wait clock signal
by the clock signal precision measuring unit 15 is carried out when
a temperature detector or a voltage detector (both not shown) incorporated
in the mobile phone detects the change in temperature or voltage.
The new counter value RV is calculated in accordance with the above
calculation equation when the frequencies of the main clock signal
and the wait clock signal change. There is a possibility that the
calculated new counter value RV has an error for a few clocks because
the main clock signal is high in frequency. When the error is generated,
the mobile phone cannot keep the continuity of the count value of
the main counter 14 and especially the mobile phone of the W-CDMA
system will fall in the operation impossible state. Therefore, to
prevent the error in the mobile phone according to the first embodiment,
the ratio RATIO is calculated and is held by the clock signal precision
measuring unit 15 when the temperature change or the voltage change
is detected. The held ratio RATIO is used for the calculation of
the new counter value RV. As a result, because any error is never
contained in the calculated new counter value RV, the continuity
of the count value of the main counter 14 is kept and the mobile
phone can continue the normal operation.
As described above, according to the mobile phone in the first
embodiment, when the present invention is applied to the mobile
phone of the W-CDMA system, the power consumption can be suppressed
because the continuity of the main counter can be kept even if the
generation of the main clock signal is stopped in the waiting operation.
Moreover, because it is not necessary to establish communication
synchronization with the base station again, it is possible to reduce
the process time after the waiting operation and suppression of
the power consumption.
The mobile phone according to the second embodiment of the present
invention has the main clock signal of 2 systems will be described.
FIG. 5 is a block diagram showing the circuit structure of the
mobile phone according to the second embodiment of the present invention.
The mobile phone is composed of a first CPU 10a, a first main clock
generator 11a, a wait clock generator 12, a wait timer 13, a first
main counter 14a, a first clock signal precision measuring unit
15a, a second CPU 10b, a second main clock generator 11b, a second
main counter 14b, and a second clock signal precision measuring
unit 15b. The first CPU 10a, the first main clock generator 11a,
the first wait timer 13a, the first main counter 14a and the first
clock signal precision measuring unit 15a are mutually connected
by a first CPU bus 20a. Also, the second CPU 10b, the second main
clock generator 11b, the second wait timer 13b, the second main
counter 14b and the second clock signal precision measuring unit
15b are mutually connected by a second CPU bus 20b.
The first CPU 10a, the first main clock generator 11a, the wait
clock generator 12, the wait timer 13, the first main counter 14a
and the first clock signal precision measuring unit 15a of a first
system section correspond to the CPU 10, the main clock generator
11, the wait clock generator 12, the wait timer 13, the main counter
14 and the clock signal precision measuring unit 15 in the first
embodiment, respectively. The functions and operations of them are
also the same as those of corresponding ones in the fist embodiment.
Also, the second CPU 10b, the second main clock generator 11b, the
wait clock generator 12, the wait timer 13, the second main counter
14b and the second clock signal precision measuring unit 15b of
a second system section correspond to the CPU 10, the main clock
generator 11, the wait clock generator 12, the wait timer 13, the
main counter 14 and the clock signal precision measuring unit 15
in the first embodiment, respectively. The functions and operations
of them are also the same as those of corresponding ones in the
fist embodiment.
According to the mobile phone in the second embodiment, because
two kinds of the main clock signals can be handled, there is an
advantage that the generality further spreads. It should be noted
that the main clock signal is not limited to two kinds and may be
three or more kinds. In the case, the mobile phone having multiple
system of main clock signal can be achieved by adding sets of the
CPU, the main clock generator, the main counter and the clock signal
precision measuring unit in accordance with the number of systems.
As described above in detail, according to the present invention,
the mobile phone can be provided in which the power consumption
can be suppressed and the process time after the waiting operation
can be decreased.
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