1. An optical line terminator (OLT), comprising:
a receiver to receive an optical signal, including packet data, from each of a plurality of optical network units (ONUs);
a power recovery to recover the received optical signal to an electrical signal having a predetermined power corresponding to the received optical signal; and
a data inserter to insert dummy data in a time interval in which the packet data is absent, in the recovered electrical signal.
2. The OLT of claim 1, wherein the optical signal comprises a clock received from a corresponding ONU.
3. The OLT of claim 1, wherein the packet data is temporally divided using a guard time interval.
4. The OLT of claim 1, wherein a generation rate of the dummy data matches a transmission rate of the packet data.
5. The OLT of claim 1, further comprising:
a Media Access Control (MAC) to determine the time interval in which the packet data is absent, and to generate a control signal based on the determination result,
wherein the data inserter inserts the dummy data according to the control signal.
6. The OLT of claim 1, wherein the power of the electrical signal corresponds to a predetermined power level.
7. The OLT of claim 1, further comprising:
a clock and data recovery (CDR) to recover packet data and a clock that are received from a corresponding ONU, from the electrical signal in which the dummy data is inserted.
8. The OLT of claim 7, wherein the CDR recovers the packet data and the clock using a phase lock loop (PLL) or a delay lock loop (DLL).
9. An optical line terminator (OLT), comprising:
a receiver to receive an optical signal, including packet data, from an optical network unit (ONU);
a dummy data generator to generate dummy data synchronized with the packet data; and
a dummy data inserter to insert the dummy data in a time interval in which the packet data is absent, in the optical signal.
10. The OLT of claim 9, further comprising:
a clock and data recovery (CDR) to recover packet data and a clock that are received from the ONU, from the optical signal in which the dummy data is inserted.
11. The OLT of claim 9, further comprising:
a Media Access Control (MAC) to determine the time interval in which the packet data is absent, and to generate a control signal based on the determination result,
wherein the data inserter inserts the dummy data according to the control signal.
12. The OLT of claim 11, wherein the CDR transmits the recovered packet data and clock to the MAC.
13. The OLT of claim 9, further comprising:
a power recovery to recover the power of the received optical signal to a predetermined power level,
wherein the dummy data inserter inserts the dummy data in the optical signal of which the power is recovered.
14. An optical network unit (ONU), comprising:
a transmitter to transmit, to an optical line terminator (OLT), an optical signal including packet data,
wherein the optical signal is converted to an electrical signal and dummy data is inserted in a time interval in which the packet data is absent, in the electrical signal.
15. The ONU of claim 14, wherein:
the transmitter includes a clock in the optical signal and transmits the optical signal including the clock, and
the packet data and the clock are recovered from the optical signal in which the dummy data is inserted.
16. The ONU of claim 14, wherein the transmitter temporally divides the packet data using a guard time interval and thereby transmits the temporally divided packet data.
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 substrate processing device comprising:
a cassette section from and into which a cassette housing a plurality of substrates constituting lots is taken and put;
a processing section to execute a plurality of processes for the substrates in sequence;
a plurality of solution processing units disposed in the processing section to process the substrates by using a predetermined processing solution;
a transfer mechanism to take out the substrates from the cassette of the cassette section and to transfer the substrates to the processing section;
substrate carrying mechanisms to receive the substrates from the transfer mechanism, to carry the substrates in sequence in the processing section, and to carry the substrates out to the cassette section;
a cyclic route disposed in the processing section, along which the substrate carrying mechanisms make cycle movements; and
a control section to make recipes which define operations of the transfer mechanism, the substrate carrying mechanisms and the solution processing units, to obtain a cycle time and a dummy dispense time based on the recipes, to obtain a substrate transfer stop period based on the recipes, the cycle time and the dummy dispense time, to stop transfer of a substrate of a succeeding lot from the cassette section to the processing section during the substrate transfer stop period, to cause the solution processing unit to execute dummy dispense during the substrate transfer stop period, and then to transfer the substrate of the succeeding lot to the processing section by the transfer mechanism.
2. The device according to claim 1,
wherein the control section comprises:
a recipe making section to make a recipe to define an operation of each of the transfer mechanism, the substrate carrying mechanisms and the solution processing units;
a recipe storing section to store the recipes made by the recipe making section;
a recipe selecting section to select and call the recipes stored in the recipe storing section;
a cycle time calculating section to calculate the cycle time based on the recipes;
a dummy dispense calculating section to calculate the dummy dispense time based on the recipes;
a transfer stop period calculating section to calculate the substrate transfer stop period based on the recipes, the cycle time and the dummy dispense time;
a counting section to count the number of the processed substrates; and
a dummy dispense determining section to decide the execution timing of the dummy dispense based on the counted number of the processed substrates and the transfer stop period.
3. The device according to claim 2,
wherein the dummy dispense determining section obtains a time interval between lots based on the recipes, and decides the execution timing of the dummy dispense based on the time interval between lots.
4. The device according to claim 2,
wherein the dummy dispense determining section obtains a minimum wafer count based on the recipes, and decides the execution timing of the dummy dispense based on the minimum wafer count.
5. The device according to claim 2,
wherein the dummy dispense determination section obtains a process recipe change timing based on the recipes, and decides the execution timing of the dummy dispense based on the process recipe change timing.
6. The device according to claim 2,
wherein the dummy dispense determining section counts the number of the continuously processed substrates after the previous dummy dispense, and determines whether or not the next dummy dispense is executed based on the counted number.