| 摘要 |
PROBLEM TO BE SOLVED: To provide a reference-pulse generator for ensuring accuracy of clock frequency. SOLUTION: Reference pulses are referred for clock-generation operation of an HDMI transmitter 36. A CPU 28 resets the clock-preparation operation of the HDMI transmitter 36, and changes the level of the reference pulses into an L level in response to overflow of a timer TM1 for OS. The CPU 28 detects the value of a free-running timer TM2 as a "CAL<SB>-</SB>START<SB>-</SB>TIME" while resetting the clock-preparation operation of the HDMI transmitter 36 at the same time. The CPU 28 further changes the level of the reference pulses into an H level in response to subsequent overflow of the timer TM1 for OS, and detects the value of the free-running timer TM2 as a "CAL<SB>-</SB>STOP<SB>-</SB>TIME" in relation to a change into the H level. When a "ΔTM" showing the difference between the "CAL<SB>-</SB>STOP-TIME" and the "CAL<SB>-</SB>START<SB>-</SB>TIME" is deviated from a predetermined range, the CPU 28 restarts the processing. The accuracy of clock frequency can be secured. COPYRIGHT: (C)2011,JPO&INPIT
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