摘要:
Provided is a DLL circuit that can execute a precise delay synchronization operation without increasing the variable delay time range of a delay line. The DLL circuit comprises a phase comparator (3), a charge pump (6), an LPF (8) and a delay line (9), and operates to match phases of an input signal (CLKIN) and a feedback signal (FBCLK). The phase comparator (3) always outputs a phase comparison result that causes a delay time of the delay line (9) to increase, at the time of initial operation after a reset operation. The LPF (8) outputs a delay adjusting signal (S8) indicating that a delay time due to the delay line (9) becomes the minimum, in executing a reset.
摘要:
A digital data transmission system for transmitting digital data, a frame pulse signal, and a clock using a required minimum number of signal lines and with a simple circuit structure is provided. A signal separation circuit (46) that receives a multiple clock (CKFP) which is a frame pulse signal (FP) multiplexed with a clock (CK) includes a clock recovery circuit (47) for reproducing a recovered clock (RCK) by synchronization with the multiple clock (CKFP) using a synchronization loop, and a frame pulse signal separation circuit (48) for separating a recovered frame pulse signal (RFP) from the multiple clock (CKFP) on the basis of the recovered clock (RCK).
摘要:
A voltage applying means applies a voltage which determines the logical value of a node to the node, with the signal at the node fixed. Then, an applied voltage removing means removes the voltage applied by the voltage applying means. First and second detecting means detects the logical value of the node before and after the voltage application and removal of the applied voltage. A judging means compares the results of detection of the first and second detecting means to judge whether or not the node is at a high impedance.
摘要:
An output circuit 1 comprises a constant current source 11, a switch 12, and an output pad 14. The switch 12 is connected between the constant current source 11 and the output pad 14. A transmission path 3 is connected to the output pad 14. The transmission path 3 is coupled to a terminator voltage V.sub.TT by a resistor for pull up. Reflection of a signal or generation of noise can be suppressed by bringing the resistance value of the resistor 4 close to a characteristic impedance of the transmission path 3. A voltage amplitude on the transmission path 3 can be determined arbitrarily by adjusting current value of the constant current source 11 and resistance value of the resistor 4.
摘要:
A current type inverter circuit or the like is obtained which operates at a high speed with a low power consumption. A reference power source 1 has one end connected to a power source VDD and the other source receiving a reference current Iref. A drain and a gate of an NMOS transistor Q1 of a current mirror circuit CM1, as an input part, receive an input current Iin. A drain of an NMOS transistor Q2 is connected to an node N1 of the other end side of the reference power source 1 as an output part. As an input part, a drain and a gate of an NMOS transistor Q3 of a current mirror circuit CM2 are connected to the node N1 while a drain of an NMOS transistor Q4 functions as an output part for outputting an output current Iout. The transistors are set so that all of the conditions TS1.gtoreq.1, TS2.gtoreq.1 and TS1.multidot.TS2>1 are satisfied where TS1 is a ratio of the size of the NMOS transistor Q2 to the size of the NMOS transistor Q1 and TS2 is a ratio of the size of the NMOS transistor Q4 to the size of the NMOS transistor Q3.
摘要:
A plurality of shift memories shifting data are connected in series, destination indicating bits indicative of data destination are stored in destination indicating bit memories corresponding to the shift memories respectively, and a searching circuit is provided adjacent to each of the destination indicating bit memories, which searching circuit searches data by searching the destination indicating bits.
摘要:
It is an object of the present invention to provide a phase comparator which can compare phase at high speed with simple structure. The phase is compared by a precharge type NAND gate including transistors (Q35-Q37). The result of comparison in the NAND gate is then outputted only in a period in which the input clock CLKref is at "1" by the NAND gate (NA 15), and thus the phase lag of the internal clock CLKint with respect to the input clock CLKref is detected. Phase lead of the internal clock CLKint with respect to the input clock CLKref is compared with interchanged relation of clocks inputted to a phase detecting portion (PD 2). Phase comparison can be made at high speed with a simple circuit including the precharge type NAND gate and the NAND gate (NA 15).
摘要:
A VCO circuit 4 of a PLL circuit 1 includes M delay time variable inverters 5.1 to 5.M which are connected in a ring shape. Load driving capability of delay time variable inverters 5.1 to 5.M is increased gradually toward output node OUT which is connected directly to load capacity CL. Accordingly, a high load driving capability is obtained without provision of a separate buffer.
摘要:
Incoming lines (I0 to I7) are connected to a space switch (2) through input data latches (1). The space switch (2) is connected to a normal/test changeover switch (12), which is connected to a normal/test changeover switch (13) through serial-to-parallel converting circuits (3), common buffer memories (4) and parallel-to-serial converting circuits (5). Space switches (6) are connected to the normal/test changeover switch (13). Outgoing lines (O0 to O7) are connected to the space switches 6 through output data latches (8). Connection states in the switches (2, 6) are placed in transposed relation to each other by a transposed connection generating circuit (10) in a test operation, so that the switches (2, 6) are directly connected to each other through the switches (12, 13). Predetermined data applied to the incoming lines are intactly used as expected values for judgement of the normal or abnormal operation of the set of switches of matrix structure.
摘要:
A current type inverter circuit used in a Current Type Ring Oscillator and a Voltage-Controlled oscillator operates at a high speed with a low power consumption. A reference power source 1 has one end connected to a power source VDD and the other source receiving a reference current Iref. A drain and a gate of an NMOS transistor Q1 of a current mirror circuit CM1, as an input part, receive an input current Iin. A drain of an NMOS transistor Q2 is connected to an node N1 of the other end side of the reference power source 1 as an output part. As an input part, a drain and a gate of an NMOS transistor Q3 of a current mirror circuit CM2 are connected to the node N1 while a drain of an NMOS transistor Q4 functions as an output part for outputting an output current Iout. The transistors are set so that all of the conditions TS1.gtoreq.1, TS2.gtoreq.1 and TS1.multidot.TS2>1 are satisfied where TS1 is a ratio of the size of the NMOS transistor Q2 to the size of the NMOS transistor Q1 and TS2 is a ratio of the size of the NMOS transistor Q4 to the size of the NMOS transistor Q3.