Delay circuit, clock control circuit and control method

1. A delay circuit, comprising:

N-stage delay units coupled in a chain, wherein:

the delay unit of each stage comprises a four-state gate circuit and an inverter circuit, an input terminal of the four-state gate circuit and an input terminal of the inverter circuit of each stage are coupled together, another input terminal of the inverter circuit is coupled to an output terminal of the inverter circuit of the next stage;

an input signal is coupled to the input terminal of the four-state gate circuit and the inverter circuit of the first stage, and is output with a certain delay of time by sequentially passing through the four-state gate circuit and the inverter circuit of each stage;

the four-state gate circuit comprises an inverter unit, a pull-up unit and a pull-down unit, wherein output terminals of the inverter unit, the pull-up unit and the pull-down unit are coupled together to an input terminal of the inverter unit of the next stage; and

the four-state gate circuit comprises inverter mode, high-level output mode, low-level output mode, and high-resistance mode.

2. The delay circuit of claim 1 , wherein

the inverter unit comprises a first PMOS transistor, a second PMOS transistor, a first NMOS transistor and a second NMOS transistor;

a gate of the first PMOS transistor and a gate of the first NMOS transistor are coupled to the input terminal of the inverter unit of the previous stage, and a drain of the first PMOS transistor and a drain of the first NMOS transistor are coupled to the input terminal of the inverter unit of the next stage;

a source of the first PMOS transistor is coupled to a drain of the second PMOS transistor, a source of the second PMOS transistor is coupled to a power supply, and a gate of the second PMOS transistor is coupled to a first control command; and

a source of the first NMOS transistor is coupled to a drain of the second NMOS transistor, a source of the second NMOS transistor is grounded, and a gate of the second NMOS transistor is coupled to a second control command.

3. The delay circuit of claim 1 , wherein

the pull-up unit comprises a third PMOS transistor,

a gate of the third PMOS transistor is coupled to a third control command,

a source of the third PMOS transistor is coupled to a power supply, and

a drain of the third PMOS transistor is coupled to the input terminal of the inverter unit of the next stage.

4. The delay circuit of claim 1 , wherein

the pull-down unit comprises a third NMOS transistor,

a gate of the third NMOS transistor is coupled to a fourth control command,

a source of the third NMOS transistor is grounded, and

a drain of the third NMOS transistor is coupled to the input terminal of the inverter unit of the next stage.

5. The delay circuit of claim 1 , wherein

the inverter circuit comprises a first inverter and a second inverter,

output terminals of the first inverter and the second inverter are coupled together,

an input terminal of the first inverter is coupled to an input terminal of the four-state gate circuit of the respective stage, and

an input terminal of the second inverter is coupled to an output terminal of the second inverter of the next stage; the first inverter is coupled to a first control command, the second inverter is coupled to a second control command.

6. A clock control circuit, configured to comprise the delay circuit of claim 1 , wherein

a clock signal and a mask signal are coupled to an input terminal of the delay circuit through a logic gate, and

an output terminal of the delay circuit is coupled to a logic circuit module.

7. The clock control circuit of claim 6 , wherein

the clock signal is coupled to an input terminal of an AND logic gate,

the mask signal is coupled to the other input terminal of the AND logic gate through an inverter, and

an output terminal of the AND logic gate is coupled to an input terminal of the delay circuit.

8. The clock control circuit of claim 6 , wherein

the clock signal and the mask signal are respectively coupled to two input terminals of a OR logic gate, and

an output terminal of the OR logic gate is coupled to an input terminal of the delay circuit.

9. A clock control method for a clock control circuit of claim 6 , comprising:

controlling, in the 0th to M−1th stages, inverter units to be turned on, pull-up units and pull-down units to be turned off, and in the Mth-stage, an inverter unit to be turned off;

controlling, in the 0th to M−1th stages, first inverters to be turned off and second inverters to be turned on, and in the Mth stage, a first inverter to be turned on and a second inverter to be turned off; and

outputting, a clock signal by passing through the inverter units of the 0th to M−1th stages, the first inverter of the Mth stage and the second inverters of the M−1th to the 0th stages.

10. The clock control method of claim 9 , wherein

the clock signal is output with a certain delay of time when the mask signal is turned off and the pull-up unit and the pull-down unit of the Mth stage are turned off.

11. The clock control method of claim 9 , wherein

the output clock signal is locked at a first level when the mask signal is turned on, and the pull-up unit of the Mth stage is turned on, and the pull-down unit of the Mth stage is turned off.

12. The clock control method of claim 9 , wherein

the output clock signal is locked at a second level when the mask signal is turned on, and the pull-up unit of the Mth stage is turned off, the pull-down unit of the Mth stage is turned on.