Receiver including a pulse amplitude modulation decoder, and a memory device including the same
A 4-level pulse amplitude modulation (PAM-4) decoder including: a comparator configured to receive first input data, second input data, and a clock signal and output first comparison data and second comparison data, wherein the first comparison data and the second comparison data are comparison results for the first input data and the second input data; a clock delay circuit configured to delay the clock signal and generate a delayed clock signal; and a time-windowed least significant bit (LSB) decoder configured to receive the first comparison data, the second comparison data, and the delayed clock signal, wherein the time-windowed LSB decoder is configured to perform a decoding when the delayed clock signal is at a first level.
1 . A 4-level pulse amplitude modulation (PAM-4) decoder comprising:
a comparator configured to receive first input data, second input data, and a clock signal and output first comparison data and second comparison data, wherein the first comparison data and the second comparison data are comparison results for the first input data and the second input data;
a clock delay circuit configured to delay the clock signal and generate a delayed clock signal; and
a time-windowed least significant bit (LSB) decoder configured to receive the first comparison data, the second comparison data, and the delayed clock signal,
wherein the time-windowed LSB decoder is configured to perform a decoding when the delayed clock signal is at a first level.
2 . The PAM-4 decoder of claim 1 , wherein each of the first input data and the second input data comprises 2-bit data, and
the first input data and the second input data comprise differential data.
3 . The PAM-4 decoder of claim 1 , wherein each of the first comparison data and the second comparison data comprises 1-bit data.
4 . The PAM-4 decoder of claim 1 , further comprising a latch electrically connected to the comparator and configured to sample the first comparison data and the second comparison data and output a most significant bit (MSB),
wherein the time-windowed LSB decoder is configured to decode the first comparison data, the second comparison data, and the delayed clock signal and output an LSB.
5 . The PAM-4 decoder of claim 1 , wherein the time-windowed LSB decoder comprises:
a clock OR gate configured to receive the first comparison data, the second comparison data, and the delayed clock signal and generate an output OR signal; and
a flip-flop electrically connected to the clock OR gate, and configured to receive the output OR signal, and output an LSB.
6 . The PAM-4 decoder of claim 5 , wherein the time-windowed LSB decoder further comprises an inverter electrically connected between the clock OR gate and the flip-flop, the inverter configured to generate a flip-flop clock signal.
7 . The PAM-4 decoder of claim 5 , wherein the time-windowed LSB decoder is configured such that the output OR signal is generated when the delayed clock signal is at the first level and the first comparison data or second comparison data is at the first level.
8 . The PAM-4 decoder of claim 5 , wherein the clock OR gate comprises:
a first transistor configured to receive the first comparison data;
a second transistor configured to receive the second comparison data; and
a third transistor configured to receive the delayed clock signal.
9 . The PAM-4 decoder of claim 1 , wherein the time-windowed LSB decoder is configured to perform the decoding based on the first comparison data and the second comparison data, in a time-window between a rising edge of the clock signal and a falling edge of the delayed clock signal.
10 . The PAM-4 decoder of claim 1 , wherein the clock delay circuit comprises an inverter and the inverter is configured to invert and delay the clock signal to generate the delayed clock signal.
11 . A receiver comprising an n-level pulse amplitude modulation (PAM-n) decoder, wherein the PAM-n decoder comprises:
a comparator receiving first input data, second input data, and a clock signal and outputting first comparison data and second comparison data, wherein the first comparison data and the second comparison data are comparison results for the first input data and the second input data;
a clock delay circuit delaying the clock signal to generate a delayed clock signal; and
a time-windowed least significant bit (LSB) decoder receiving the first comparison data, the second comparison data, and the delayed clock signal,
wherein the time-windowed LSB decoder performs a decoding when the delayed clock signal is at a first level.
12 . The receiver of claim 11 , wherein the PAM-n decoder comprises a PAM-4 decoder,
each of the first input data and the second input data comprises 2-bit data and each of the first comparison data and the second comparison data comprises 1-bit data, and
the first input data and the second input data comprise differential data.
13 . The receiver of claim 12 , wherein the PAM-4 decoder further comprises a latch electrically connected to the comparator and sampling the first comparison data and the second comparison data to output a most significant bit (MSB),
wherein the time-windowed LSB decoder decodes the first comparison data, the second comparison data, and the delayed clock signal and outputs an LSB.
14 . The receiver of claim 11 , wherein the time-windowed LSB decoder comprises:
a clock OR gate receiving the first comparison data, the second comparison data, and the delayed clock signal and generating an output OR signal;
a flip-flop electrically connected to the clock OR gate, receiving the output OR signal, and outputting an LSB; and
an inverter electrically connected between the clock OR gate and the flip-flop and generating a flip-flop clock signal.
15 . The receiver of claim 14 , wherein the time-windowed LSB decoder is configured such that the output OR signal is generated when the delayed clock signal is at the first level and the first comparison data or second comparison data is at the first level.
16 . The receiver of claim 15 , wherein the time-windowed LSB decoder is configured to perform the decoding based on the first comparison data and the second comparison data, in a time-window between a rising edge of the clock signal and a falling edge of the delayed clock signal.
17 . A memory device comprising an interface configured to receive input data based on n-level pulse amplitude modulation (PAM-n), wherein the interface comprises a PAM-n decoder, and
the PAM-n decoder comprises:
a comparator that receives first input data, second input data, and a clock signal and outputs first comparison data and second comparison data, wherein the first comparison data and the second comparison data are comparison results for the first input data and the second input data;
a clock delay circuit that delays the clock signal to generate a delayed clock signal; and
a time-windowed least significant bit (LSB) decoder that receives the first comparison data, the second comparison data, and the delayed clock signal,
wherein the time-windowed LSB decoder performs a decoding when the delayed clock signal is at a first level.
18 . The memory device of claim 17 , wherein the time-windowed LSB decoder comprises:
a clock OR gate that receives the first comparison data, the second comparison data, and the delayed clock signal and generates an output OR signal;
a flip-flop electrically connected to the clock OR gate, wherein the flip-flop receives the output OR signal, and outputs an LSB; and
an inverter electrically connected between the clock OR gate and the flip-flop, wherein the inverter generates a flip-flop clock signal.
19 . The memory device of claim 17 , wherein the PAM-n decoder comprises a PAM-4 decoder,
each of the first input data and the second input data comprises 2-bit data and each of the first comparison data and the second comparison data comprises 1-bit data, and
the first input data and the second input data comprise differential data.
20 . The memory device of claim 18 , wherein the time-windowed LSB decoder is configured such that the output OR signal is generated when the delayed clock signal is at the first level and the first comparison data or second comparison data is at the first level, and
the time-windowed LSB decoder performs the decoding based on the first comparison data and the second comparison data, in a time-window between a rising edge of the clock signal and a falling edge of the delayed clock signal.