Abstract: In an in-circuit emulator system, an in-circuit emulator debugger operated on a personal computer requests operation clock frequency, and transmits data for clock frequency designated by a user to an in-circuit emulator. The in-circuit emulator stores the received clock frequency data in a frequency data register. A PLL synthesizer oscillates with frequency based on the clock frequency data stored in the frequency data register to generate a clock.

Abstract: A program preparation apparatus that can reduce power consumption and that can suppress malfunctions and the occurrence of noise by improving software is provided. An assembler prepares a relative object program based on an assembly source program. Next, the assembler changes the order of instructions included in the assembly source program in a range that does not influence the operational results in a CPU and, thereby, prepares another assembly source program so as to prepare a relative object program based on this assembly source program. Next, the assembler finds the respective maximum Hamming distance values between respective instructions for a plurality of relative object programs so that the program of which the maximum Hamming distance value is the lowest is determined as a formal relative object program.

Abstract: A microcomputer includes reloadable registers for prestoring count values corresponding to an ineffective interval and an effective interval which are set in accordance with the timing of a first edge and a second edge of a head pulse signal, and for setting these count values sequentially into a counter. Only when the first edge and second edge are input at predetermined timing through an event input terminal, that is, only when the head pulse signal is input, the interrupt signal is generated for changing the operation mode from a low current consumption mode to a normal operation mode. This makes it possible to prevent a mode transition due to noise, and reduce the power consumption of the microcomputer by making more effective use of the low current consumption mode by improving a mode transition identification rate.

Abstract: In an in-circuit emulator system, an in-circuit emulator debugger operated on a personal computer requests operation clock frequency, and transmits data for clock frequency designated by a user to an in-circuit emulator. The in-circuit emulator stores the received clock frequency data in a frequency data register. A PLL synthesizer oscillates with frequency based on the clock frequency data stored in the frequency data register to generate a clock.

Abstract: When a manufacturer or a user desires to adjust a Braun tube, it is required to display a test pattern satisfying setting conditions of display modes on the Braun tube. To set the display modes of the test pattern, a plurality of horizontal synchronizing signals and a vertical synchronizing signal are generated by a timer circuit for each field. Also, display modes (for example, shape, position, size, color and luminance) of a type of characters having the same shape are set in an OSD circuit to set the display modes of the test pattern composed of the characters having the same shape. Thereafter, a composite video signal of the test pattern satisfying the display modes is produced on the basis of the horizontal synchronizing signals and the vertical synchronizing signal in the OSD circuit, and the test pattern is displayed on the Braun tube according to the composite video signal.