Abstract: An electronic system with a self-test function has a pseudo-random test pattern generator that serially generates data constituting a pseudo-random test pattern, and stores a 1-bit shifted pseudo-random test pattern obtained by shifting the pseudo-random test pattern by one bit. When a scan-path circuit supplies the pseudo-random test pattern to a tested circuit which carries out an operation based on the pseudo-random test pattern, and then loads an operation result of the tested circuit, the 1-bit shifted pseudo-random test pattern is supplied to the tested circuit as the next pseudo-random test pattern. This makes it possible to solve a problem of a conventional electronic system in that it takes a long time to evaluate the operation results of the tested circuit because it takes at least (1+n)×m clock cycles, where m is the number of pseudo-random test patterns supplied to the tested circuit and n is the number of stages of the scan-path circuit.

Abstract: A semiconductor integrated circuit device has a redundancy circuit such that when a parallel/serial conversion circuit converts the separation information of a program element group such as one fuse element group to serial data, the serial data is transmitted through a serial/parallel conversion circuit, thus controlling circuits to be controlled such as a plurality of RAMs. Further by introducing a CRC technique in the parallel/serial conversion circuit, even when there is an error input such as cutting error of the fuse element, the information may be reproduced.

Abstract: A semiconductor integrated circuit device includes a memory circuit and a flag generator. The memory circuit is a circuit with a test circuit and includes a redundant circuit. The flag generator loads compared result information serially output from the memory circuit, and outputs flag signals if the compared result information includes at least one piece of mismatch information. This makes it possible to solve a problem of a conventional semiconductor integrated circuit device in that it takes a long time for carrying out a fault test of bits constituting the memory circuit.

Abstract: A semiconductor integrated circuit device has a redundancy circuit such that when a parallel/serial conversion circuit converts the separation information of a program element group such as one fuse element group to serial data, the serial data is transmitted through a serial/parallel conversion circuit, thus controlling circuits to be controlled such as a plurality of RAMs. Further by introducing a CRC technique in the parallel/serial conversion circuit, even when there is an error input such as cutting error of the fuse element, the information may be reproduced.

Abstract: When the RAM (10) is not initialized, data signals captured from the data output portions (do[n]) may include undefined value, but these data signals are not transferred to an MISR through the scan path (22). Transferred to the MISR are only the data signals (DI[n]) captured by the scan path (13). Accordingly, BIST can be applied to the combinational logic circuit (40) without requiring initialization of the RAM (10) and without being affected by undefined value. Thus, BIST to the combinational logic circuit (40) can be normally achieved in a short period.

Abstract: In the first test mode with a shift-mode signal (SM) of “1” and a test-mode signal (TM) of “1”, supplying a comparison control signal (CMP) of “1” makes a test-valid condition. Then, a comparison result between input data (D) which becomes “0” to indicate a failure and an expected value data (EXP) (an output of a comparator (21)) and an AND-operation result between a serial input (SI) and a latch data (an output of a D-FF (27)) are given to the D-FF (27) through NAND gates (28 and 29), an AND gate (30) and a selector (26). With this configuration achieved is a semiconductor integrated circuit having a test circuit which allows a quick recognition of whether there is a failure or not in an internal memory circuit under test.

Abstract: In a self-repairing operation, a first self-test of a RAM is performed at a first temperature to obtain a first RAM test result, a RAM built-in self-test circuit judges according to the first RAM test result that a faulty portion exists in the RAM, an LSI built-in self-repair circuit judges that the repair of the faulty portion of the RAM is possible, the LSI built-in self-repair circuit controls a redundancy control circuit to avoid the use of the faulty portion of the RAM in a normal operation, the temperature of the RAM is risen by operating the RAM or a logical circuit in a pseudo-self-test to change the first temperature to a second temperature, a second self-test of the RAM is performed at the second temperature to obtain a second RAM test result, and the LSI built-in self-repair circuit confirms that the repair of the faulty portion of the RAM is possible at each of the first and second temperatures by comparing the second RAM test result with the first RAM test result.

Abstract: A semiconductor integrated circuit device has a RAM (1) which has a plurality of memory cell groups containing memory cells of a number corresponding to the number of words used, and a RAM (30, 40, 50, or 60) as a redundant circuit which has memory cell group containing memory cells of a number corresponding to the number of words of the RAM (1). Either one of data from the RAM (1) and data from the RAM (30, 40, 50, or 60) is selected by a selector circuit (5) to use the latter as a redundant circuit.

Abstract: In a normal operation, a shift mode signal (SM) is set to "0" to propagate signals applied to "0"-input ends of selectors (10 to 12), i.e., outputs of a logic unit (80). In a logic scan test on logic units (80, 81), by setting a test-mode signal to "1", an ordinary scan test is performed with a scan path of simple configuration, having bits as much as write data and employing scan flip flops consisting of pairs of selectors (10 to 12) and flip flops (30 to 32) respectively. The flip flops used for writing in the normal operation can be also used as those used for the scan flip flops in the logic test. Thus, a configuration of the scan path to achieve excellent area-efficiency is provided.

Abstract: In a small-size device, one input terminals of a plurality of AND circuits are connected in series. The other terminals of the plurality of AND circuits receive failure information held by a register circuit. Among the AND circuits, by changing values at the AND circuits which are connected in an output direction (i.e., most significant bit side) of an AND circuit receiving a failure bit and values at the AND circuits which are connected in an input direction (i.e., least significant bit side) of the AND circuit receiving the failure bit, a signal line associated with the failure bit is disconnected and signal lines are re-connected to adjacent signal lines including an extra line by selectors. Hence, a failure bit is compensated in a very simple structure.

Abstract: In a normal mode, a logic test signal (LOGTEST), a RAM test signal (RAMTEST), and a shift mode signal (SM) are set to "0". A RAM core (91) is synchronously written and asynchronously read. In a logic test mode, the RAM test signal (RAMTEST) is set to "0", and the logic test signal (LOGTEST) is set to "1". In a RAM test mode, the RAM test signal (RAMTEST) is set to "1", and the logic test signal (LOGTEST) is set to "0". A scan path (3a) is used both as a scan path provided between logic portions (82, 83) in the logic test and as a scan path provided at the output of the RAM core (91) in the RAM test. The scan path provides a high area utilization efficiency.

Abstract: A connection circuit (CC) is formed by selectors (2,3) and a flip-flop (4). Th selectors (2,3) are switch-controlled by a test holding control signal (thld) and a shift mode control signal (sm) respectively. A scan-in terminal (si) is connected to a data input 0 terminal of the selector (2), while an output terminal of the flip-flop (4) is connected to its data input 1 terminal. An output terminal of the selector (2) is connected to a data input 1 terminal of the selector (3). An input terminal (d) is connected to a data input 0 terminal of the selector (3). An output terminal of the selector (3) is connected to an input terminal of the flip-flop (4). The output terminal of the flip-flop (4) is also connected to a scan-out terminal (so) and an output terminal (q) of the connection circuit (CC). In an ordinary operation, data is inputted through the input terminal (d). Thus, a scan path forming circuit attaining a high-speed operation in an ordinary operation is provided.

Abstract: Automatic generation of a test pattern for test data to test a content addressable memory for failure is disclosed. An inverter (INV1) inverts a scan signal (SODI) outputted from a scan path to apply the inverted scan signal to a 1-input of a selector (SEL1). A scan input (SIDI) is the inverted version of a scan output from a scan flip-flop (SFF-D12). To test a content addressable memory (100), a test signal (CAMTEST) is set to "1", thereby producing input signals (DI0, DI1, DI2) in such a looped manner as: (0, 0, 0).fwdarw.(1, 0, 0).fwdarw.(1, 1, 0).fwdarw.(1, 1, 1).fwdarw.(0, 1, 1).fwdarw.(0, 0, 1).fwdarw.(0, 0, 0).fwdarw. . . . .

Abstract: A semiconductor memory in which integration is enhanced is provided. An NMOS transistor Qn1 has a gate connected to a write word line WWLn, a source connected to a write bit line WBLn, and a drain connected to a node N1. An NMOS transistor Qn2 has a gate connected to a read word line RWLn and a source connected to a read bit line RBLn. An NMOS transistor Qn3 has a gate connected to the drain of the NMOS transistor Qn1, a source connected to a ground level, and a drain connected to the drain of the NMOS transistor Qn2. An NMOS transistor Qn4 has a gate connected to a ground level, a source connected to the source of the NMOS transistor Qn3, and a drain connected to the drain of the NMOS transistor Qn1. The NMOS transistor Qn4 is kept off so that the drain of the NMOS transistor Qn1 is dielectrically isolated from the source of the NMOS transistor Qn3.

Abstract: Multi-port RAM having a RAM core and signal transfer circuit transforming a predetermined signal between the RAM core and a random logic portion. The signal transfer circuit includes a scan path circuit. The scan path circuit for an address signal (ASCAN0), a scan path circuit for a data input signal (DSCAN0) and a selector circuit (ASEL) are provided on the write side, and no scan path circuit is provided on the read side. A read address is supplied through selector circuits (FSEL 2 and RSEL2) termed read address supply device provided on the read side. Thus, reduction of the test circuit allows area reduction of a chip and cost cutting in a semiconductor integrated circuit.

Abstract: When stored data of a plurality of memory cells (MC00 to MC03, MC10 to MC13, MC20 to MC23, MC30 to MC33) arranged in a matrix are sequentially read out, a reading access control circuit (101) outputs a row address and a column address to a row decoder (102) and a reading bit-line selector (103), respectively, for an access to the memory cells. The reading access control circuit (101) outputs the row address and the column address so that an n-type memory cell may be first selected by the reading bit-line selector (103) after activation of the selected reading word line every time one of the reading word lines (RWL0 to RWL3) is selected by the row decoder (102). With this configuration, data can be sequentially read out at higher speed from a plurality of memory cells arranged in a matrix.

Abstract: In a small-size device, one input terminals of a plurality of AND circuits are connected in series. The other terminals of the plurality of AND circuits receive failure information held by a register circuit. Among the AND circuits, by changing values at the AND circuits which are connected in an output direction (i.e., most significant bit side) of an AND circuit receiving a failure bit and values at the AND circuits which are connected in an input direction (i.e., least significant bit side) of the AND circuit receiving the failure bit, a signal line associated with the failure bit is disconnected and signal lines are re-connected to adjacent signal lines including an extra line by selectors. Hence, a failure bit is compensated in a very simple structure.

Abstract: A programming of memory cells in an upper block (UB) is reversely made, thereby obtaining reverse data which are opposite to desired data when the upper block (UB) is selected. An inverter circuit (IV) is additionally provided at an output of a sense amplifier (SA1) and inverts the reverse data, thus eventually obtaining the desired data. Having such configuration as to reduce the number of ON/OFF controllable memory cells, a semiconductor memory device which cuts power consumption is provided. Moreover, with OFF-state memory cells having such configuration as to suppress application of load (charge) capacity to bit lines and word lines as much as possible, the semiconductor memory device which ensures high-speed access to the memory cells is provided.

Abstract: In order to obtain a flip-flop circuit which reduces an S/H time or a T-Q delay while suppressing power consumption, a master latch is formed by a dynamic half latch having a transmission gate (S1) and an invertor (INV1), while a slave latch is formed by a static half latch having transmission gates (S3, S4) and invertors (INV3, INV4). In the slave latch, the operation of the transmission gate (S4) is controlled not only by a clock signal (T) but by a mode signal (MODE). When the mode signal (MODE) is converted to a low level, the transmission gate (S4) enters a nonconducting state, so that the slave latch performs a dynamic operation.

Abstract: To switch redundancy circuit properly by performing tests by equipment itself such as semiconductor unit or computer containing semiconductor unit, etc. without using any expensive laser unit. Relieves failure by controlling selectors SEL1 to SEL4 with control memory cells C11 to C14 connected respectively to a plural number of external bit lines OBL1 to OBL4 and by switching the relation of correspondence between the external bit lines OBL1 to OBL4 and the internal bit lines BL1 to BL5. The data to the control memory cells C11 to C14 is given from the external bit lines OBL1 to OBL4.