Memory card and host device thereof
A memory card is attached to a host device, and includes a data control circuit which transfers data with respect to the host device in synchronism with a rise edge and a fall edge of a clock signal.
1. A storage device comprising:
a command terminal;
a plurality of data terminals;
a clock terminal;
a power terminal for a power supply voltage;
a ground terminal for a ground voltage;
a nonvolatile memory; and
a controller coupled to the command terminal, the data terminals, the clock terminal, the power terminal, and the ground terminal, wherein:
the controller is configured to receive a clock signal through the clock terminal from an outside of the storage device;
the controller is configured to output data through at least one of the data terminals to the outside of the storage device, in accordance with only one of a rising edge and a falling edge of the clock signal, in a first transfer mode;
the controller is configured to output data through at least one of the data terminals to the outside of the storage device, in accordance with both the rising edge and the falling edge of the clock signal, in a second transfer mode;
the controller is configured to receive a first command of a check function whose mode bit being a first value through the command terminal from the outside of the storage device;
the controller is configured to output first status data that includes information indicating that the storage device supports the second transfer mode, through one of the data terminals to the outside of the storage device, in response to the first command of the check function whose the mode bit being the first value;
the controller is configured to receive a first command of a set function whose the mode bit being a second value through the command terminal from the outside of the storage device;
the controller is configured to set the storage device into the second transfer mode in response to the first command of the set function whose the mode bit being the second value;
the first value and the second value of the mode bit in the first command respectively determines the check function and the set function; and
the storage device switches the check function and the set function in response to the first value and the second value of the mode bit in the first command.
2. The storage device according to claim 1 , wherein the controller is configured to read data from the nonvolatile memory and output the read data through at least one of the data terminals.
3. The storage device according to claim 2 , wherein the nonvolatile memory is a NAND type flash memory.
4. The storage device according to claim 1 , wherein the controller is configured to output second status data that includes information indicating that the storage device is set into the second transfer mode, through one of the data terminals to the outside of the storage device, in response to the first command of the set function whose the mode bit being the second value.
5. The storage device according to claim 1 , wherein:
the first status data includes data fields of a plurality of function groups; and
the second transfer mode is assigned to one of the function groups.
6. The storage device according to claim 5 , wherein the number of the function groups is six.
7. The storage device according to claim 1 , wherein the first status data further includes information on a maximum consumption current required for the second transfer mode.
8. The storage device according to claim 1 , wherein:
the controller is configured to output data through at least one of the data terminals to the outside of the storage device, in accordance with the clock signal having a first frequency, in a normal bus mode;
the controller is configured to output data through at least one of the data terminals to the outside of the storage device, in accordance with the clock signal having a second frequency, in a high-speed bus mode;
the second frequency is higher than the first frequency; and
the first status data further includes information indicating that the storage device supports the high-speed bus mode.
9. The storage device according to claim 1 , wherein:
the first status data further includes information indicating that the storage device supports an IC card function; and
the controller is configured to validate the IC card function of the storage device in response to the first command of the set function whose the mode bit being the second value.
10. The storage device according to claim 1 , wherein the first status data further includes information on a command system.
11. The storage device according to claim 1 , wherein the controller is configured to output a response to the first command through the command terminal to the outside of the storage device.
12. The storage device according to claim 1 , wherein:
the controller is configured to receive a second command through the command terminal from the outside of the storage device; and
the controller is configured to stop outputting data through at least one of the data terminals to the outside of the storage device, in response to the second command.
13. The storage device according to claim 1 , wherein:
the controller is configured to output data in a plurality of data blocks, through at least one of the data terminals to the outside of the storage device; and
a CRC code is added to each of the data blocks.
14. The storage device according to claim 1 , wherein:
the controller is configured to output data through all data terminals to the outside of the storage device, in a first bit mode; and
the controller is configured to output data through only one of the data terminals to the outside of the storage device, in a second bit mode.