1. A construction machine comprising:
a rotating motor for causing a rotating operation of a part of the construction machine;
actuators including an arm cylinder for causing operation of an arm of the construction machine;
a plurality of hydraulic pumps;
control valves positioned and adapted to control supply and discharge of oil between the hydraulic pumps and each of the actuators, said control valves including a control valve for the rotating motor and a control valve for the arm cylinder;
a switching valve switchable between a first position and a second position, wherein the switching valve is positioned and adapted such that when the switching valve is in the first position the switching valve separately supplies oil from the hydraulic pumps to the control valve for the rotating motor and the control valve for the arm cylinder, and when the switching valve is in the second position the switching valve unites the oil from the hydraulic pumps;
a detector adapted to output signals responsive to a rotating operation and an arm operation, respectively;
a switching controller adapted to receive the output signals from the detector, and to switch the switching valve to the second position when signals responsive to a rotating operation and an arm operation are output substantially simultaneously; and
a meter-in flow controller adapted to restrict a quantity of oil supplied to the arm cylinder when the switching valve is switched to the second position.
2. The construction machine according to claim 1, further comprising a meter-out flow controller adapted to restrict a quantity of oil discharged from the arm cylinder when the switching valve is switched to the second position.
3. The construction machine according to claim 2, wherein said meter-in flow controller and said meter-out flow controller are adapted to control a quantity of throttling according to the magnitude of said rotating operation.
4. The construction machine according to claim 1, wherein said construction machine has an engine, and wherein said meter-in flow controller is adapted to change throttle characteristics according to a rotational frequency of the engine.
5. The construction machine according to claim 2, wherein said construction machine has an engine, and wherein said meter-out flow controller is adapted to change throttle characteristics according to a rotational frequency of the engine.
6. The construction machine according to claim 1, wherein said meter-in flow controller is housed in said control valve for the arm cylinder.
7. The construction machine according to claim 1, further comprising:
left and right traveling motors;
traveling motor control valves for controlling said traveling motors; and
wherein said switching valve is adapted to switch between independently supplying oil from said hydraulic pumps to both said traveling motor control valves in said first position, and supplying oil from a single hydraulic pump in said second position.
8. In a hydraulic control circuit comprising:
a plurality of actuators including a rotating motor for causing a rotating operation of a part, and an arm cylinder for causing an arm operation;
a plurality of hydraulic pumps;
control valves positioned and adapted to control supply and discharge of oil between the hydraulic pumps and each of the actuators, said control valves including two control valves for the rotating motor and a control valve for the arm cylinder;
a switching valve switchable between a first position and a second position, wherein the switching valve is positioned and adapted such that when the switching valve is in the first position the switching valve separately supplies oil from the hydraulic pumps to the control valves for the rotating motor and the control valve for the arm cylinder, and when the switching valve is in the second position the switching valve unites the oil from the hydraulic pumps;
detectors adapted to output signals when the rotating and the arm operation are carried out;
a switching controller adapted to switch said switching valve to said second position when the rotating and arm operation signals are output simultaneously, and
a meter-in throttle adapted to throttle a quantity of oil supplied to said arm cylinder when said switching valve is switched to said second position.
9. A construction machine comprising:
a rotating motor for causing a rotating operation of a part of the construction machine;
actuators including an arm cylinder for causing operation of an arm of the construction machine;
a plurality of hydraulic pumps;
control valves positioned and adapted to control supply and discharge of oil between the hydraulic pumps and each of the actuators, said control valves including a control valve for the rotating motor and a control valve for the arm cylinder;
a switching valve means positionable in a first position for separately supplying oil from the hydraulic pumps to the control valve for the rotating motor and the control valve for the arm cylinder, and positionable in a second position for uniting the oil from the hydraulic pumps;
detector means for outputting signals responsive to a rotating operation and an arm operation, respectively;
switching controller means for receiving the output signals from the detector, and for switching the switching valve means to the second position when signals responsive to a rotating operation and an arm operation are output substantially simultaneously; and
meter-in flow control means for restricting a quantity of oil supplied to the arm cylinder when the switching valve means is switched to the second position.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A program method for a multi-level phase change memory device, comprising:
receiving multi-level data to be programmed in a selected memory cell; and
applying a program signal to the selected memory cell according to the received multi-level data,
wherein a rising time of the program signal is set to be longer than a falling time of the program signal.
2. The program method of claim 1, wherein the received multi-level data corresponds to one of a lowest state, a highest state, and a plurality of intermediate states between the lowest state and the highest state.
3. The program method of claim 2, wherein when the received multi-level data corresponds to one of the intermediate states, the rising time of the program signal is set to be longer than the falling time of the program signal.
4. The program method of claim 3, wherein voltage levels of program signals corresponding respectively to the intermediate states are set differently depending on the intermediate states.
5. The program method of claim 4, wherein rising slopes of program signals corresponding respectively to the intermediate states are set equally regardless of the intermediate states.
6. The program method of claim 5, wherein the program signal is set to have a sustain time between the rising time and the falling time.
7. The program method of claim 3, wherein voltage levels of program signals corresponding respectively to the intermediate states are set equally regardless of the intermediate states.
8. The program method of claim 7, wherein rising slopes of program signals corresponding respectively to the intermediate states are set differently depending on the intermediate states.
9. The program method of claim 8, wherein the program signal is set to have a sustain time between the rising time and the falling time.
10. The program method of claim 3, wherein voltage levels of program signals corresponding respectively to the intermediate states are set equally regardless of the intermediate states; and rising slopes of program signals corresponding respectively to the intermediate states are set differently depending on the intermediate states.
11. The program method of claim 10, wherein the program signal is set to have a sustain time between the rising time and the falling time.
12. The program method of claim 2, wherein when the received multi-level data corresponds to one of the intermediate states, the program signal has a triangular waveform whose rising time is set to be longer than a falling time.
13. A multi-level phase change memory device comprising:
a memory cell array comprising a plurality of memory cells;
a selector circuit configured to select at least one of the memory cells; and
a write driver circuit configured to apply a program signal to the selected memory cell according to multi-level data to be programrmed in the selected memory cell,
wherein a rising time of the program signal is set to be longer than a falling time of the program signal.
14. The multi-level phase change memory device of claim 13, wherein the multi-level data corresponds to one of a lowest state, a highest state, and a plurality of intermediate states between the lowest state and the highest state.
15. The multi-level phase change memory device of claim 14, wherein when the multi-level data corresponds to one of the intermediate states, the rising time of the program signal is set to be longer than the falling time of the program signal.
16. The multi-level phase change memory device of claim 15, wherein the program signal is set to have a sustain time between the rising time and the falling time.
17. The multi-level phase change memory device of claim 13, wherein when the multi-level data corresponds to one of the intermediate states, the program signal has a triangular waveform whose rising time is set to be longer than a falling time.
18. A memory card comprising a multi-level phase change memory device that operates according to the program method of claim 1.
19. A computing system comprising a multi-level phase change memory device of claim 13.