Memory systems and controllers for generating a command address and methods of operating same
A memory system includes a host system having a memory controller therein, which is configured to generate a command address signal. The memory controller includes a first bit signal generator configured to generate a data signal as a plurality of data bits, a second bit signal generator configured to generate a command address bus inversion bit (CABIB) having a high or low logic level that is a function of a number of data bits within the data signal having a predetermined logic level, and a parity bit generator configured to set a parity signal to a first logic level when a total number of data bits within the data signal and the CABIB having a high logic level is an even number. A storage system is also provided, which is configured to write or read data in response to the command address signal received from the host system. The memory controller is configured to set the CABIB to a high logic level when: (i) “n”, which is a number of bits included in the command address signal, is a positive integer greater than one, and (ii) a number of data bits within the data signal having a low logic level is greater than or equal to (n/2)−1.
1. A memory system, comprising:
a host system including a memory controller configured to generate a command address signal, said memory controller comprising:
a first bit signal generator configured to generate a data signal as a plurality of data bits;
a second bit signal generator configured to generate a command address bus inversion bit (CABIB) having a high or low logic level that is a function of a number of data bits within the data signal having a predetermined logic level; and
a parity bit generator configured to set a parity signal to a first logic level when a total number of data bits within the data signal and the CABIB having a high logic level is an even number; and
a storage system configured to write or read data in response to the command address signal received from the host system.
2. The system of claim 1 , wherein the memory controller is configured to set the CABIB to a high logic level when: (i) “n”, which is a number of bits included in the command address signal, is a positive integer greater than one, and (ii) a number of data bits within the data signal having a low logic level is greater than or equal to (n/2)−1.
3. The system of claim 1 , wherein the memory controller is configured to set a level of the parity signal to a low logic level when the number of data bits within the data signal and the CABIB having a high logic level is an odd number.
4. The system of claim 1 , wherein the memory controller is configured to set a level of the parity signal to a high logic level when the number of data bits within the data signal and the CABIB having a high logic level is an even number.
5. The system of claim 1 , wherein the storage system includes an error detector configured to detect an error within the command address signal; and wherein the error detector is configured to determine that there is no error in the command address signal when a number of signals having the high logic level within the command address signal is an odd number.
6. The system of claim 5 , wherein the error detector is configured to invert the data bits within the data signal when a level of the CABIB is a high logic level.
7. The system of claim 1 , wherein, when the number of data bits within the data signal is 18, the memory controller sets a level of the CABIB to the low logic level when the number of data bits within the data signal having the low logic level is greater than or equal to 9.
8. The system of claim 7 , wherein the memory controller is configured to maintain levels of the plurality of data bits.
9. The system of claim 1 , wherein, when the number of data bits within the data signal is 18, the memory controller sets a level of the CABIB to the high logic level when the number of data bits within the data signal having the low logic level is less than 9.
10. The system of claim 9 , wherein the memory controller is configured to invert levels of the plurality of data bits.
11. A method of operating a memory system, comprising:
generating, by a memory controller, a command address signal to be transmitted to a memory device; and
writing or reading data to or from a storage device within a storage system based on the command address signal, which is received by the storage system;
wherein said generating comprises:
generating a data signal including a plurality of data bits;
generating a command address bus inversion bit (CABIB) having one of a high logic level and a low logic level based on a number of data bits within the data signal having a low logic level; and
generating a parity bit to a high logic level when a sum of: (i) a total number of data bits having the high logic level within the data signal, and (ii) the CABIB, is an even number.
12. The method of claim 11 , wherein the CABIB is set to a high logic level when: (i) “n”, which is a number of bits included in the command address signal, is a positive integer greater than one, and (ii) a number of data bits having a low logic level within the data signal is greater than or equal to (n/2)−1.
13. The method of claim 11 , wherein said generating includes setting the parity bit to a low logic level when a sum of: (i) the number of data bits within the data signal having a high logic level, and (ii) the CABIB, is an odd number.
14. The method of claim 11 , wherein said generating includes setting the parity bit to a high logic level when a sum of: (i) the number of data bits within the data signal having a high logic level, and (ii) the CABIB, is an even number.
15. The method of claim 11 , wherein during said generating, if the number of data bits within the data signal is 18, a level of the CABIB is set to a low logic level when the number of data bits having the low logic level is greater than or equal to 9.
16. The method of claim 15 , wherein levels of the plurality of data bits are maintained during said generating of the command address signal.
17. The method of claim 11 , wherein during said generating, if the number of data bits within the data signal is 18, a level of the CABIB is set to the high logic level when the number of data bits having low logic level is less than 9.
18. The method of claim 17 , wherein the memory controller inverts levels of the plurality of data bits.
19. A memory controller, which controls an operation of a host system for generating a command address, comprising:
a first bit signal generator configured to generate a data signal including a plurality of data bits;
a second bit signal generator configured to generate a command address bus inversion bit (CABIB) having one of a high logic level and a low logic level based on a number of signals having the low logic level included in the plurality of data bits; and
a parity bit generator configured to set a parity signal to a high logic level when a number of signals having a high logic level among signals included in the plurality of data bits and the command address bus inversion bit is an even number.
20. The memory controller of claim 19 , wherein, when n is a number of bits included in the command address signal having a natural number greater than or equal to 2 and a number of bits having a low logic level included in the plurality of data bits is greater than or equal to (n/2)−1, and the number of signals having the high logic level among the signals included in the plurality of data bits and the CABIB is an odd number, the memory controller sets the CABIB to a high logic level and sets a level of a parity signal to a low logic level.