摘要:
A communication system includes: a master; a plurality of slaves; and a bus for coupling among the master and the plurality of slaves in order to communicate asynchronously among the master and the plurality of slaves. The master supplies electricity to the bus in a power supply period. The master or the slave drives the bus for transmitting a one-bit data through the bus in a data transmission period. The power supply period and the data transmission period are successively performed so that data communication provided by a plurality of one-bit periods is performed among the master and the plurality of slaves. The master finely changes a communication frequency in the data communication. The master changes a drive level of the bus within a predetermined acceptable range in the data communication.
摘要:
A communication system includes a master control unit, a plurality of slave control units, and buses connecting the master control unit and the slave control units for the asynchronous communication. When the master control unit starts the communication, each slave control unit transmits a plurality of data bits represented by whether the buses be driven to the master control unit in data transmission periods assigned to the slave control units based on a start of communication, and the master control unit drives the buses to insert a period for supplying power while data bits are being transmitted in the data transmission period. The slave control unit provides a non-driving period, which stops driving the buses, at an end of the data bit transmission period.
摘要:
A communication system includes: a master; a plurality of slaves; and a bus for coupling among the master and the plurality of slaves in order to communicate asynchronously among the master and the plurality of slaves. The master supplies electricity to the bus in a power supply period. The master or the slave drives the bus for transmitting a one-bit data through the bus in a data transmission period. The power supply period and the data transmission period are successively performed so that data communication provided by a plurality of one-bit periods is performed among the master and the plurality of slaves. The master finely changes a communication frequency in the data communication. The master changes a drive level of the bus within a predetermined acceptable range in the data communication.
摘要:
A communication system includes: a master; a plurality of slaves; and a bus for coupling among the master and the plurality of slaves in order to communicate asynchronously among the master and the plurality of slaves. The master supplies electricity to the bus in a power supply period. The master or the slave drives the bus for transmitting a one-bit data through the bus in a data transmission period. The power supply period and the data transmission period are successively performed so that data communication provided by a plurality of one-bit periods is performed among the master and the plurality of slaves. The master finely changes a communication frequency in the data communication. The master changes a drive level of the bus within a predetermined acceptable range in the data communication.
摘要:
A communication system includes a master control unit, a plurality of slave control units, and buses connecting the master control unit and the slave control units for the asynchronous communication. When the master control unit starts the communication, each slave control unit transmits a plurality of data bits represented by whether the buses be driven to the master control unit in data transmission periods assigned to the slave control units based on a start of communication, and the master control unit drives the buses to insert a period for supplying power while data bits are being transmitted in the data transmission period. The slave control unit provides a non-driving period, which stops driving the buses, at an end of the data bit transmission period.
摘要:
A communication system includes: a master; a plurality of slaves; and a bus for coupling among the master and the plurality of slaves in order to communicate asynchronously among the master and the plurality of slaves. The master supplies electricity to the bus in a power supply period. The master or the slave drives the bus for transmitting a one-bit data through the bus in a data transmission period. The power supply period and the data transmission period are successively performed so that data communication provided by a plurality of one-bit periods is performed among the master and the plurality of slaves. The master finely changes a communication frequency in the data communication. The master changes a drive level of the bus within a predetermined acceptable range in the data communication.
摘要:
A microcomputer for functioning according to operation modes includes: a mode counter that counts the number of times of level change in a signal applied to a mode setting terminal; a mode decoder that decodes output data of the mode counter to output a mode signal, which represents one operation mode; a clock input terminal; a data terminal through which serial data is inputted synchronously with a serial clock signal applied to the clock input terminal; a serial-to-parallel conversion unit that converts the serial data into parallel data and stores the parallel data in an input data buffer; and a switching means that switches to a state that a CPU can access to the input data buffer in a test mode. In the test mode, test instruction data is capable of being inputted from an external circuit.
摘要:
In a power supply circuit, when switches are turned off, current flows from a battery power supply line through resistors, input terminals, diodes and a terminal and further from a terminal into IC. When a microcomputer operates in a low power consumption operating mode, the power supply voltage is higher than a target voltage, and a control voltage output from an operational amplifier increases, so that a transistor is turned off. At this time, a current sink circuit operates and a transistor is turned on, so that excessive current flows into the current sink circuit to suppress increase of the power supply voltage.
摘要:
A microcomputer for functioning according to operation modes includes; a mode counter that counts the number of times of level change in a signal applied to a mode setting terminal; a mode decoder that decodes output data of the mode counter to output a mode signal, which represents one operation mode; a clock input terminal; a data terminal through which serial data is inputted synchronously with a serial clock signal applied to the clock input terminal; a serial-to-parallel conversion unit that converts the serial data into parallel data and stores the parallel data in an input data buffer; and a switching means that switches to a state that a CPU can access to the input data buffer in a test mode. In the test mode, test instruction data is capable of being inputted from an external circuit.
摘要:
A CPU, when shifting to a sleep mode, discontinues the oscillating operations of an oscillation circuit and of a frequency multiplier circuit through a low power consumption control circuit. A flash power source circuit discontinues the oscillating operations of the circuits or interrupts or resumes the supply of an external power source in response to resumption of the halted operation. When the CPU is to be shifted to the sleep mode, the frequency multiplier circuit holds the set oscillation control conditions. When the oscillating operation is to be resumed, operates based on the oscillation control conditions that are held. When the sleep mode is reset, the CPU makes access to the mask ROM and immediately reads out a control program that is to be executed right after the wakeup.