摘要:
A signal line, being in a six-layer board and connecting terminal 102 of component 101 with terminal 115 of component 114, requires tamper-resistance. The signal line is composed of foil 103 on an outside layer, a via 104, foil 111 on the third layer, via 105, foil 112 on the fourth layer, via 106, and foil 113 on the sixth layer. Portions of the signal line that exist on outside layers are all hidden under circuit components. Foil 103 and an end of via 104 are placed under component 101 on first layer 116, an end of via 105 is placed under component 107 on layer 116, an end of via 106 is placed under component 108 on layer 116, the other end of via 104 is placed under component 109 on sixth layer 121, the other end of via 105 is placed under component 110 on layer 121, and foil 113 and the other end of via 106 are placed under component 114 on layer 121.
摘要:
A design aiding apparatus and a method, and a storage medium storing a design aiding program enable the efficient layout design of components in a multilayer wiring board formed by laminating a plurality of wiring layers. The design aiding apparatus includes (a) a first acquiring unit for acquiring information showing a first location in a lamination direction of the wiring layers, (b) a second acquiring unit for acquiring information showing a second location on a two-dimensional plane that is orthogonal to the lamination direction, and (c) a placement unit for generating information showing a space to be occupied when the component is placed in such a manner that a placement reference point of the component coincides with the second location that is on the two-dimensional plane including the first location. According to the above construction, the present invention is capable of aiding layout design of components in the wiring board.
摘要:
A collective erasure type nonvolatile semiconductor memory device which allows use of redundant structure to word lines is provided. A row address buffer having address converting function simultaneously selects a plurality of physically adjacent word lines from a memory array in programming before erasure. Programming before erasure is effected on the memory cells on the simultaneously selected word lines. Even when physically adjacent word lines are short-circuited between each other, programming high voltage can be transmitted to the defective word lines, as these word lines are selected simultaneously. Therefore, the memory cells on the defective word lines can be programmed before erasure, so that over erasure at the time of collective erasing operation can be prevented. Thus, redundant structure for replacing defecting word lines by spare word lines can be utilized.
摘要:
Disclosed is a flash EEPROM including a voltage lowering circuit therein for lowering an externally applied high voltage serving as a source of an erase pulse to a predetermined voltage in a range in which a tunnel phenomenon sufficiently occurs in memory cells. The voltage lowered by the voltage lowering circuit is converted into a pulse of a small width, and the converted pulse is then applied as an erase pulse to the memory cells. A flash EEPROM including a memory cell array divided into first and second blocks is also disclosed. An erase pulse applying circuit for applying the voltage lowered by the voltage lowering circuit as an erase pulse to the memory cells, and an erase verify circuit for erase verifying are provided for each of the first and second blocks. The erase pulse applying circuit and the erase verify circuit corresponding to the first block and the ones corresponding to the second block are configured to operate independently.
摘要:
A foldable electronic print board copies or records, on recording paper, various patterns of information, including letters, numerals, images, etc., which have been handwritten on a writing sheet. The foldable electronic print board has a pair of hinged cases housing the writing sheet, and a printer for printing the handwritten information on the recording paper. The printer is detachably mounted on the cases across the axis about which the print board is foldable, to keep the print board unfolded. Since the printer itself is used to hold the print board unfolded, no dedicated holder or holders are required to be fixed to the cases. The printer is located at the geometric center of the print board for thereby making the print board stable in use.
摘要:
An electronic typewriter comprises a printing head, a carriage on which the printing head is movable along along a printing line, a keyboard including various keys, a carriage pointer for indicating the position at which the carriage is presently located, a line buffer having sequential memory locations corresponding to printing positions on the printing line, and a control circuit for performing a character key processing when a character key is operated and a space key processing when a space key is operated. In the electronic typewriter, the control means is constructed so as to perform a carriage return processing when a carriage return key is operated, in which processing the spelling of such a word is checked that one of the characteristic codes forming the word or a space code following the word is stored in a memory location of said line buffer specified by the carriage pointer, the carriage and carriage pointer are retuned to a predetermined home position thereafter, and the returning of carriage and carriage pointer is omitted when an error is detected in the spelling check.
摘要:
In a semiconductor integrated circuit such as a semiconductor memory device capable of operating in a special mode in addition to a standard operation mode, a high voltage detection circuit 10 detects a high voltage applied to one of control signal input terminals CS and outputs a detection signal HV to a special mode circuit 14. The special mode circuit 14 outputs a switch signal CO to a switching circuit 11 in response to the detection signal HV. The switching circuit 11 connects an input/output buffer 7 to a latch circuit 12 in response to the switch signal CO. A special mode code MC is applied to input/output terminals DT and transmitted to the latch circuit 12 through the switching circuit 11. A special mode decoder 13 decodes the special mode code MC which has been latched by the latch circuit 12 and outputs a signal for specifying the special mode to a control circuit 8. Operation in the special mode specified by the control circuit 8 is executed. By detecting a confirmation signal CS applied to one of the control signal input terminals CS during the execution of the special mode, the special mode code MC which has been already latched by the latch circuit 12 can be outputted from the input/output terminals DT.
摘要:
A semiconductor memory device of erasable programmable rear only memory type is disclosed the memory device has a pair of memory cell arrays between which a differential amplifier is provided. Each of the memory cell arrays has a current-to-voltage converter circuit associated therewith. When a memory cell in either one of the pair of memory cell array is selected, a bit line being coupled to the selected memory cell is charged by one current-voltage conversion circuit, while at the same time at least one bit line in the other memory cell array where no memory cell has been selected is charged by the associated current-voltage converter circuit at arrayed different from the bit line coupled to the selected memory cell. A differential amplifier senses and amplifies a potential difference between the charged bit lines to provide a high speed read-out of the memory device.
摘要:
A nonvolatile semiconductor memory device comprises memory cells each formed of a single memory transistor and can be accessed in a bit-by-bit manner to eliminate an erase cycle in a data write cycle. The memory device comprises precharging circuits for precharging word lines and bit lines in the data write cycle, tri-level V.sub.pp switches, in response to a data to be written and an output of X decoder, for applying to a selected word line a write voltage V.sub.pp when the data to be written is "1" while a ground potential when the data to be written is "0", and further applying remaining non-selected word lines the precharge voltage, and tri-level V.sub.pp switches, in response to a data to be written and an output of Y decoder, for applying to a selected bit line the ground potential when the data to be written is "1" while the write high-voltage V.sub.pp when the data to be written is "0", and further to the remaining non-selected bit lines the precharge voltage.
摘要:
An EEPROM provided with a write/erase checking circuit comprising, a data detector for determining whether one byte in an input data contains a "0" (representing that a memory cell is not in an erase state); an address latch circuit and a data latch circuit which latch the address and the input data, respectively, responsive to a detection signal from the data detector; a data read circuit which selects the memory cells according to the address stored in the address latch circuit and reads the data out of the memory cells at the data write checking; and a comparator which compares the data from the data read circuit with the data stored in the data latch circuit.