Generating a parallel data signal by converting serial data of a serial data signal to parallel data
Methods and deserializer circuits are provided for generating a parallel data signal by converting serial data of a serial data signal to parallel data. In a particular embodiment, the deserializer circuit includes a logic divider configured to generate based on a half rate clock, a quarter rate clock, a mode rate clock, and a selection control signal. The deserializer circuit includes a first set of latches for sampling and aligning the serial data from the serial data signal into the deserializer circuit based on the half rate clock. The deserializer circuit also includes a shift register including a second set of latches configured to latch the output of the first set of latches based on the quarter rate clock generated by the logic divider. In the particular embodiment, the deserializer circuit also includes multiplexer logic configured to output the parallel data signal including latching data from the shift register.
1. A deserializer circuit for generating a parallel data signal by converting serial data of a serial data signal to parallel data, the parallel data signal including one of: eight bits of parallel data and ten bits of parallel data, the deserializer circuit including:
a logic divider configured to generate based on a half rate clock, a quarter rate clock, a mode rate clock, and a selection control signal; wherein the mode rate clock is aligned to the quarter rate clock such that each positive edge of the mode rate clock occurs between a negative edge of the quarter rate clock and the next consecutive positive edge of the quarter rate clock which follows the negative edge of the quarter rate clock;
wherein the mode rate clock is aligned to the selection control signal such that the positive edge of the mode rate clock is after a negative edge of the quarter rate clock and before the next consecutive edge of the selection control signal which follows the negative edge of the quarter rate clock;
a first set of latches for sampling and aligning the serial data from the serial data signal into the deserializer circuit based on the half rate clock;
a shift register including a second set of latches configured to latch the output of the first set of latches based on the quarter rate clock generated by the logic divider; and
multiplexer logic configured to output the parallel data signal including latching data from the shift register,
wherein data is latched into the second set of latches in the shift register such that the first ten bits of a particular data sequence of the serial data are available during an entire clock cycle of the quarter rate clock and that the next two bits of the particular data sequence are available for only a second half of a cycle of the quarter rate clock.
2. The deserializer circuit of claim 1 wherein the first set of latches include sampling latches with two separate paths of latches, each separate path of latches configured to:
sample one half of the serial data signal; and
generate a stream of data based on the one half of the serial data signal.
3. The deserializer circuit of claim 2 wherein the first set of latches include a data aligner, wherein the data aligner is configured to align the two streams of data from the sampling latches.
4. The deserializer circuit of claim 3 wherein both streams of data are aligned to the positive edge of the half rate clock.
5. The deserializer circuit of claim 1 wherein the logic divider includes a first divide-by-two counter to generate the quarter rate clock and a second divide/by-two counter/divide-by-three counter to generate an eighth rate clock and a twelfth rate clock.
6. The deserializer circuit of claim 1 wherein the mode rate clock is an eighth rate clock during an eight bit deserialization operation mode of the deserializer; wherein the mode rate clock alternates between an eighth rate clock and a twelfth rate clock during a ten bit deserialization operation mode of the deserializer.
7. The deserializer circuit of claim 1 wherein during an eight bit deserialization operation mode of the deserializer, the selection control is one; wherein during a ten bit deserialization operation mode of the deserializer, the selection control is one when the mode rate clock is an eighth rate clock and the selection control is zero when the mode rate clock is a twelfth rate clock.
8. A method of generating a parallel data signal by converting serial data of a serial data signal to parallel data, the parallel data signal including one of: eight bits of parallel data and ten bits of parallel data, the method comprising:
generating based on a half rate clock, by a logic divider of the deserializer, a quarter rate clock, a mode rate clock, and a selection control signal; wherein the mode rate clock is aligned to the quarter rate clock such that each positive edge of the mode rate clock occurs between a negative edge of the quarter rate clock and the next consecutive positive edge of the quarter rate clock which follows the negative edge of the quarter rate clock;
wherein the mode rate clock is aligned to the selection control signal such that the positive edge of the mode rate clock is after a negative edge of the quarter rate clock and before the next consecutive edge of the selection control signal which follows the negative edge of the quarter rate clock;
generating, by a first set of latches, an output including sampling and aligning, the serial data from the serial data signal into the deserializer circuit based on the half rate clock;
latching based on the quarter rate clock, by a second set of latches of a shift register of the deserializer, the output of the first set of latches; and
outputting, by multiplexer logic of the deserializer, the parallel data signal including latching data from the shift register,
wherein data is latched into the second set of latches in the shift register such that the first ten bits of a particular data sequence of the serial data are available during an entire clock cycle of the quarter rate clock and that the next two bits of the particular data sequence are available for only a second half of a cycle of the quarter rate clock.
9. The method of claim 8 wherein the first set of latches include sampling latches with two separate paths of latches, each separate path of latches configured to:
sample one half of the serial data signal; and
generate a stream of data based on the one half of the serial data signal.
10. The method of claim 9 wherein the first set of latches include a data aligner, wherein the data aligner is configured to align the two streams of data from the sampling latches.
11. The method of claim 10 wherein both streams of data are aligned to the positive edge of the half rate clock.
12. The method of claim 8 wherein the logic divider includes a first divide-by-two counter to generate the quarter rate clock and a second divide-by-two counter/divide-by-three counter to generate an eighth rate clock and a twelfth rate clock.
13. The method of claim 8 wherein the mode rate clock is an eighth rate clock during an eight bit deserialization operation mode of the deserializer; wherein the mode rate clock alternates between an eighth rate clock and a twelfth rate clock during a ten bit deserialization operation mode of the deserializer.
14. The method of claim 8 wherein during an eight bit deserialization operation mode of the deserializer, the selection control is one; wherein during a ten bit deserialization operation mode of the deserializer, the selection control is one when the mode rate clock is an eighth rate clock and the selection control is zero when the mode rate clock is a twelfth rate clock.
15. A deserializer circuit for generating a parallel data signal by converting serial data of a serial data signal to parallel data, the parallel data signal including one of: eight bits of parallel data and ten bits of parallel data, the deserializer circuit including:
a logic divider configured to generate based on a half rate clock, a quarter rate clock, a mode rate clock, and a selection control signal; wherein the mode rate clock is aligned to the quarter rate clock such that each positive edge of the mode rate clock occurs between a negative edge of the quarter rate clock and the next consecutive positive edge of the quarter rate clock which follows the negative edge of the quarter rate clock;
wherein the mode rate clock is aligned to the selection control signal such that the positive edge of the mode rate clock is after a negative edge of the quarter rate clock and before the next consecutive edge of the selection control signal which follows the negative edge of the quarter rate clock;
a first set of latches for sampling and aligning the serial data from the serial data signal into the deserializer circuit based on the half rate clock;
a shift register including a second set of latches configured to latch the output of the first set of latches based on the quarter rate clock generated by the logic divider; and
multiplexer logic configured to output the parallel data signal including latching data from the shift register.
16. The deserializer circuit of claim 1 wherein the first set of latches include sampling latches with two separate paths of latches, each separate path of latches configured to:
sample one half of the serial data signal; and
generate a stream of data based on the one half of the serial data signal.
17. The deserializer circuit of claim 1 wherein the logic divider includes a first divide-by-two counter to generate the quarter rate clock and a second divide/by-two counter/divide-by-three counter to generate an eighth rate clock and a twelfth rate clock.
18. The deserializer circuit of claim 1 wherein the mode rate clock is an eighth rate clock during an eight bit deserialization operation mode of the deserializer; wherein the mode rate clock alternates between an eighth rate clock and a twelfth rate clock during a ten bit deserialization operation mode of the deserializer.