Command signal clock gating
View Patent ↗A semiconductor device includes a clock gating tree comprising a first clock gating stage and a second clock gating stage. The first clock gating stage is configured to receive an activate detection signal and to activate clocking events in the second clock gating stage in response to the activate detection signal. The clocking events are not activated in the absence of the activate detection signal.
1. A semiconductor device, comprising:
a clock gating tree comprising a first clock gating stage and a second clock gating stage, wherein the first clock gating stage is configured to receive an activate detection signal and to activate clocking events in the second clock gating stage in response to the activate detection signal, wherein the clocking events are not activated in the absence of the activate detection signal, wherein the semiconductor device comprises a double data rate type five synchronous dynamic random access memory (DDR5 SDRAM) device.
2. The semiconductor device of claim 1 , wherein the first clock gating stage comprises a flip-flop and the second clock gating stage comprises a plurality of flip-flops.
3. The semiconductor device of claim 2 , wherein in response to receiving the activate detection signal, the flip-flop in the first clock gating stage latches the activate detection signal based on a clock signal and outputs a clock enabling signal to activate clocking of the plurality of flip-flops.
4. The semiconductor device of claim 2 , wherein the plurality of flip-flops comprise fourteen flip-flops configured to latch command/address signals in response to the activated clocking events.
5. The semiconductor device of claim 4 , comprising logic configured to determine the activate detection signal based on types of the command signals.
6. The semiconductor device of claim 1 , wherein the semiconductor device comprises a command decoder, and wherein the command decoder comprises the clock gating tree.
7. A semiconductor device, comprising:
a synchronous digital circuit configured to receive command address signals, wherein the synchronous digital circuit comprises a clock gating tree, comprising:
a first clock gating stage comprising a first flip-flop configured to be latched based on a clock signal; and
a second clock gating stage comprising a plurality of second flip-flops, wherein the plurality of second flip-flops are configured to be latched in response to an activate detection signal latched by the first flip-flop based on the clock signal, and wherein the plurality of second flip-flops comprise fourteen flip-flops configured to latch the command address signals in response to the activate detection signal latched by the first flip-flop.
8. The semiconductor device of claim 7 , comprising logic coupled to the first clock gating stage and configured to provide the activate detection signal to an input of the first flip-flop.
9. The semiconductor device of claim 8 , wherein the logic provides the activate detection signal based on command address signals received from a device external to the semiconductor device.
10. The semiconductor device of claim 7 , wherein the command address signals comprise:
a command portion transferred on a first clock cycle of the clock signal; and
an address portion transferred on a second clock cycle of the clock signal.
11. The semiconductor device of claim 7 , wherein the plurality of second flip-flops are not clocked on every clock cycle of the clock signal.
12. The semiconductor device of claim 7 , wherein in response to the activate detection signal, the plurality of second flip-flops are configured to be clocked to latch the command address signals to one or more bank control blocks of one or more memory banks.
13. The semiconductor device of claim 7 , wherein the semiconductor device is a synchronous dynamic random access memory (SDRAM) device.
14. A method, comprising:
receiving, at a first clock gating stage of a synchronous digital circuit, an activating signal;
latching the activating signal to an output of the first clock gating stage based on a clock signal; and
sending a clock enabling signal to activate clocking of a second clock gating stage;
latching command/address signals from an input of the second clock gating stage to an output of the second clock gating stage based on the clock enabling signal; and
transferring a command portion of the command/address signals in a first clock cycle and transferring an address portion of the command/address signals in a second clock cycle.
15. The method of claim 14 , wherein:
receiving the activating signal comprises receiving, at an input of a flip-flop, the activating signal; and
latching the activating signal comprises latching the activating signal to an output of the flip-flop.
16. The method of claim 14 , wherein:
sending the clock enabling signal comprises sending the clock enabling signal to activate clocking a plurality of flip-flops; and
latching the command/address signals comprises latching the command/address signals from an input of each of the plurality of flip-flops to an output of each of the plurality of flip-flops.
17. The method of claim 16 , wherein latching the command/address signals is based on the activating signal received by the first clock gating stage.
18. The method of claim 14 , comprising generating the activating signal by logic, based on the command/address signals.
19. The method of claim 14 , comprising utilizing the command/address signals to access one or more memory banks.