Synchronous type semiconductor device for high speed data processing
View Patent ↗Disclosed is a synchronous semiconductor device including clock generation circuit that frequency divides a clock signal (PCLK) input from an input buffer and generates first and second internal clock signals having a predetermined phase difference from first and second frequency-divided clock signals of different phases, respectively, a first input circuit control unit that receives a chip select signal and samples the chip select signal in synchronization with the clock signal, second and third input circuit control units that sample an output of the first input circuit control unit in synchronization with the first and second internal clock signals, respectively, and first and second input circuits that receive a result of a logic operation between the output of the first input control unit and an output of the second input circuit control unit and a result of a logic operation between the output of the first input circuit control unit and an output of the third input circuit control unit as input enable signals, respectively, and sample an externally input signal in synchronization with the first and second internal clock signals, respectively based on enabling instructed by the input enable signals.
1. A synchronous type semiconductor device comprising:
a clock generation circuit that receives an input clock signal and generate first and second internal clock signals having a predetermined phase difference therebetween;
a first circuit that samples an input chip select signal in synchronization with the input clock signal;
second and third circuits that receive an output signal of said first circuit in common and sample the output signal in synchronization with the first and second internal clock signals, respectively; and
first and second input buffers that receive a result of a logic operation between the output signal of said first circuit and an output signal of said second circuit and a result of a logic operation between the output signal of said first circuit and an output signal of said third circuit as first and second input enable signals, respectively, and sample a common input signal in synchronization with the first and second internal clock signals, respectively, based on enabling instruction by the first and second input enable signals.
2. A synchronous type semiconductor device comprising:
a clock generation circuit that generates first and second internal clock signals having a predetermined phase difference from first and second frequency-divided clock signals having different phases, respectively, the first and second frequency-divided clock signals being obtained by frequency dividing an input clock signal by a frequency divider;
a first circuit that samples an input chip select signal in synchronization with the input clock signal when the second frequency-divided clock signal is active;
a second circuit that samples the input chip select signal in synchronization with the input clock signal when the first frequency-divided clock signal is active;
a third circuit that samples an output signal of said first circuit in synchronization with the first internal clock signal;
a fourth circuit that samples an output signal of said second circuit in synchronization with the second internal clock signal; and
first and second input buffers that receive a result of a logic operation between the output signal of said first circuit and an output signal of said third circuit and a result of a logic operation between the output signal of said second circuit and an output signal of said fourth circuit as first and second input enable signals, respectively, and sample a common input signal in synchronization with the first and second internal clock signals, respectively, based on enabling instructed by the first and second input enable signals.
3. A synchronous type semiconductor device comprising:
a clock generation circuit that receives an input clock signal and generate first and second internal clock signals having a predetermined phase difference therebetween;
a first circuit that samples an input chip select signal in synchronization with the input clock signal;
second and third circuits that receive an output signal of said first circuit in common and sample the output signal in synchronization with the first and second internal clock signals, respectively;
first and second input buffers that receive a result of a logic operation between the output signal of said first circuit and an output signal of said second circuit and a result of a logic operation between the output signal of said first circuit and an output signal of said third circuit as first and second input enable signals, respectively, and sample a common input signal in synchronization with the first and second internal clock signals, respectively, based on enabling instruction by the first and second input enable signals;
a third input buffer that receives a clock signal; and
a fourth input buffer that receives a chip select signal;
wherein said clock generation circuit includes:
a frequency divider that receives a clock signal output from said first input buffer, frequency divides the clock signal, and outputs frequency-divided clock signals; and
a timing adjusting unit that receives the frequency-divided clock signals output from said frequency divider and generates first and second internal clock signals having a predetermined phase difference;
wherein said first circuit includes a first input circuit control unit that receives an output signal of said second input buffer and an output signal of said first input buffer, and samples the output signal of said second input buffer in synchronization with the output signal of said first input buffer;
wherein said second circuit includes a second input circuit control unit that receives an output signal of said first input circuit control unit and the first internal clock signal from said timing adjusting unit, and samples the output signal of said first input circuit control unit in synchronization of the first internal clock signal;
wherein said third circuit includes a third input circuit control unit that receives the output signal of said first input circuit control unit and the second internal clock signal from said timing adjusting unit, and samples the output signal of said first input circuit control unit in synchronization with the second internal clock signal; and
wherein said semiconductor device further comprises:
a first logic circuit that receives the output signal of said first input circuit control unit and an output signal of said second input circuit control unit, and outputs a result of a logic operation between the two output signals; and
a second logic circuit that receives the output signal of said first input circuit control unit and an output signal of said third input circuit control unit, and outputs a result of a logic operation between the two output signals.
4. The synchronous type semiconductor device according to claim 3 , wherein said first input buffer receives an output signal of said first logic circuit as a first input control signal and latches an address signal supplied to an input terminal in synchronization with the first internal clock signal, when the first input control signal is active; and
said second input buffer receives an output of said second logic circuit as a second input control signal and latches the address signal in synchronization with the second internal clock signal, when the second input control signal is active.
5. The synchronous type semiconductor device according to claim 3 , wherein said first input circuit control unit includes a latch circuit that latches the output signal of said second input buffer based on the output signal of said first input buffer;
said second input circuit control unit includes a latch circuit that latches the output signal of said first input circuit control unit based on the first internal clock signal; and
said third input circuit control unit includes a latch circuit that latches the output signal of said first input circuit control unit based on the second internal clock signal.
6. The synchronous type semiconductor device according to claim 3 , wherein each of said first and second logic circuits comprises an OR circuit.
7. A synchronous type semiconductor device comprising:
a first input buffer that receives a clock signal;
a frequency divider that receives a clock signal output from said first input buffer, frequency divides the clock signal, and outputs first and second frequency-divided clock signals having phases thereof being different to each other;
a timing adjusting unit that receives the first and second frequency-divided clock signals from said frequency divider and generates first and second internal clock signals having a predetermined phase difference therebetween in association with the first and second frequency-divided clock signals, respectively;
a second input buffer that receives a chip select signal;
a first input circuit control unit that receives an output signal of said second input buffer and the output signal of said first input buffer, receives the second frequency-divided clock signal as an input control signal, and samples the output signal of said second input buffer in synchronization with the output signal of said first input buffer when the second frequency-divided clock signal is active;
a second input circuit control unit that receives the output signal of said second input buffer and the output signal of said first input buffer, receives the first frequency-divided clock signal as an input control signal, and samples the output signal of said second buffer in synchronization with the output signal of said first input buffer when the first frequency-divided clock signal is active;
a third input circuit control unit that receives an output signal of said first input circuit control unit and the first internal clock signal from said timing adjusting unit, and samples the output signal of said first input circuit control unit in synchronization with the first internal clock signal;
a fourth input circuit control unit that receives an output signal of said second input circuit control unit and the second internal clock signal from said timing adjusting unit, and samples the output signal of said second input circuit control unit in synchronization with the second internal clock signal;
a first logic circuit that receives the output signal of said first input circuit control unit and an output signal of said third input circuit control unit, and outputs a result of a logic operation between the two output signals; and
a second logic circuit that receives the output signal of said second input circuit control unit and an output signal of said fourth input circuit control unit, and outputs a result of a logic operation between the two output signals.
8. The synchronous type semiconductor device according to claim 7 , comprising:
a third input buffer that receives an output signal of said first logic circuit as a first input control signal and latches an address signal supplied to an input terminal in synchronization with the first internal clock signal, when the first input control signal is active; and
a fourth input buffer that receives an output of said second logic circuit as a second input control signal and latches the address signal in synchronization with the second internal clock signal, when the second input control signal is active.
9. The synchronous type semiconductor device according to claim 7 , wherein: said first input circuit control unit includes a latch circuit that latches the output signal of said second input buffer based on the output signal of said first input buffer when the second frequency-divided clock signal is active; and
said second input circuit control unit includes a latch circuit that latches the output signal of said second input buffer based on the output signal of said first input buffer when the first frequency-divided clock signal is active.
10. The synchronous type semiconductor device according to claim 7 , wherein said third input circuit control unit includes a latch circuit that latches the output signal of said first input circuit control unit based on the first internal clock signal; and
said fourth input circuit control unit includes a latch circuit that latches the output signal of said second input circuit control unit based on the second internal clock signal.
11. The synchronous type semiconductor device according to claim 7 , wherein each of said first and second logic circuits comprises an OR circuit.