Abstract: Integrated circuits in which a phase difference between the external and internal clocks can be reduced by decreasing transistor stages from the input of an external clock to the output of an internal clock drive stages and also noise can be reduced which is generated when the clock driver drives at a high speed the internal clock having a heavy load and the noise can be prevented from propagation to other portions to avoid having a bad effect on other circuits, and further the internal clock having the same phase can be supplied to each part of the chip even at a high operating frequency by minimizing skew of the internal clock signal on the chip and still further a demand current can be reduced by eliminating a passing current of the internal clock signal driver.

Abstract: A microprocessor which, following a reset signal, permits execution beginning from an arbitrary address. The microprocessor is constituted in a manner such that arbitrary data is set in advance in a data register as an address. The address in the data register is given to a program counter by a register indirect jump instruction which does not originate in the instruction ROM. The microprocessor has a resetting function in addition to the normal resetting function. The normal resetting function includes re-executing a program from a predetermined address, such as a zero address. The normal resetting function occurs in the case where the logical level of a control signal input terminal is a predetermined level at a point of time when the reset signal to the reset terminal is cleared. When the control signal is at a different level, the arbitrary data set in the data register is transferred to the program counter by the register indirect jump instruction and is set in the program counter.

Abstract: Integrated circuits in which a phase difference between the external and internal clocks can be reduced by decreasing transistor stages from the input of an external clock to the output of an internal clock drive stages and also noise can be reduced which is generated when the clock driver drives at a high speed the internal clock having a heavy load and the noise can be prevented from propagation to other portions to avoid having a bad effect on other circuits, and further the internal clock having the same phase can be supplied to each part of the chip even at a high operating frequency by minimizing skew of the internal clock signal on the chip and still further a demand current can be reduced by eliminating a passing current of the internal clock signal driver.

Abstract: A serial data input circuit of this invention which, at the time of inputting of serial data, stores a predetermined signal represented in the bit outputted from the output side of the shift register when the last bit of serial data is inputted into the input side of a shift register and signals other than the predetermined signal in other bits respectively, so that, when all the bits of serial data are inputted into the shift register, the predetermined signal is outputted from the shift register, thereby realizing the circuit of small-sized, of simple in circuitry construction without a counter or the like.

Abstract: An adder circuit includes a Manchester-carry-chain circuit which propagates a carry signal for each block consisting of plural bits, and a carry-look-ahead circuit which selects said carry signal in response to a carry propagation signal being generated by a full adder, and when the carry signal is not generated in the two consecutive blocks, an output from the Manchester-carry-chain circuit is selected by the carry-look-ahead circuit, so that the carry signal being inputted to the low-order block of the two blocks can be propagated as the carry signal to be outputted from the high-order block.

Abstract: Integrated circuits in which a phase difference between the external and internal clocks can be reduced by decreasing transistor stages from the input of an external clock to the output of an internal clock drive stages and also noise can be reduced which is generated when the clock driver drives at a high speed the internal clock having a heavy load and the noise can be prevented from propagation to other portions to avoid having a bad effect on other circuits, and further the internal clock having the same phase can be supplied to each part of the chip even at a high operating frequency by minimizing skew of the internal clock signal on the chip and still further a demand current can be reduced by eliminating a passing current of the internal clock signal driver.

Abstract: Apparatus is disclosed for a self-test function internal to a semiconductor integrated circuit. The invention includes an internal random number generator for generating test data for use by a self-test program. As a result of the invention, external equipment is not necessary for executing the self-test, internal memory for storing for self-test data can be decreased, and self-test can be performed readily by the user. Furthermore, since self-test result data is compressed so as to be compared with the data of prediction values, the data of the test result can be reduced for easy processing.

Abstract: A microprocessor utilizing Harvard Architecture is disclosed with a data space for data storage, an instruction space for instruction storage, and a common space implemented as a high-speed on-chip RAM that functions as a continuous extension of both the data space and the instruction space, for the simultaneous and flexible storage of data and instructions.

Abstract: A clock frequency divider for generating a basic clock signal which provides operation timing for a semiconductor integrated circuit operating in accordance with a program. The clock frequency divider comprises a frequency-dividing factor register for storing a frequency-dividing factor which can be rewritten by the program, and a frequency-dividing circuit for frequency-dividing a source clock signal having a fixed frequency in accordance with the frequency-dividing factor stored in the frequency-dividing factor register, whereby a basic clock which provides a processing rate optimum for a program to be executed being obtained.

Abstract: As the incrementer of the invention comprises a shift register for its lower order bits, while its higher bit portions are constructed in the same way as a conventional incrementer, the incrementer can give output signals directly to a memory and the like without the necessity of decoding the same, and the incrementer is free from carry propagation delay possibilities, which assures an improved rate of operation of the incrementer as a whole.

Abstract: A multiple digit comparator checks the first and the second input data for a match. If the two input data match, the carry input data from the previous digit is outputted as the carry output data for the next digit; if the two input data do not match, then a no match signal is outputted as the carry output data for the next digit. Next, if the carry input data and the carry output data do not match then a change point signal is outputted. When this change point signal is outputted, the first and the second input data are outputted. This facilitates the design of a more regular comparator circuit layout and of a faster comparator circuit.

Abstract: The operation speed of a full adder is increased by avoiding the necessity of forming the inverse signal for adder operation and deleting the time required for passing through an inverter.

Abstract: A semiconductor integrated circuit includes an auxiliary instruction register group having a plurality of auxiliary instruction registers capable of setting in advance the content by a program, and one of the auxiliary instruction register selected by the output of the decoder or controls a portion of the semiconductor integrated circuit that is not controlled by the instruction of the instruction register or controls a portion while cooperating with the instruction register. Thus, the integrated circuit can effectively perform a control of large degree of freedoms in a short instruction register.

Abstract: A memory circuit 14 comprises a MOS transistor 15 having its threshold voltage selected to be higher than the output voltage on the occasion of the ordinary operation. Consequently, the MOS transistor 15 is off on the occasion of the ordinary operation, and a ratio latch 4 performs the ordinary storing operation. Meanwhile, if the output voltage of the power source 12 is raised, the MOS transistor 15 turns on to pull down the potential of a data input line 6a to the ratio latch. Accordingly, the ratio latch 4 is forced to be set.

Abstract: First and second semiconductor circuits are interconnected by a transmission circuit within an integrated circuit powered by a common voltage supply. The first semiconductor circuit is operative when the voltage applied to the integrated circuit is at a first or a second level different from a ground potential whereas the second semiconductor circuit is operative when the first level is applied and is inoperative when the second level is applied to the integrated circuit. The first semiconductor circuit controls the second semiconductor circuit selectively in test and operative modes as the applied voltage is varied between the first and second levels.