Non-volatile memory card and transfer interruption means
View Patent ↗A memory card is provided with a transfer control circuit, a write control circuit and a judging circuit. The transfer control circuit outputs a transfer flag signal during the data transfer. The write control circuit outputs an internal busy signal during the data write operation. The judging circuit outputs a transfer interruption signal when a card selection signal of the host is negated during the input of the transfer flat signal and also outputs a suspension signal when the card selection signal is negated during the input of the internal busy signal. A CPU invalidates the data being transfer to interrupt the transfer process upon reception of the transfer interruption signal and completes, upon reception of the suspension signal, the process being executed and stays in the waiting condition. Consequently, even when the timing signal not conforming to the standards is transferred, the host can select the optimum processing operation from the internal processing conditions and thereby execute the selected operation.
1. A multimedia card comprising a flash memory, which includes a plurality of non-volatile memory cells to store data, and a controller which instructs operations of said flash memory based on commands issued from a host,
wherein said controller is provided with a process judging portion, the process judging portion outputs a transfer interruption signal when a card selection signal for selecting said multimedia card is transitioned to a disable state from an enable state while said host is transferring data for storing to ones of said plurality of non-volatile memory cells and before starting to store the transferred data to ones of said plurality of non-volatile memory cells, and
wherein said controller invalidates transferred data and interrupts the transfer process in response to the transfer interruption signal.
2. The multimedia card according to claim 1 , wherein said process judging portion comprises:
a transfer control unit which detects that data is being transferred from said host and outputs a transfer flag signal; and
a process judging unit that receives said transfer flag signal outputted from said transfer control unit and a card selection signal for selecting said multimedia card, and outputs said transfer interruption signal when said card selection signal transitions from the enable state to the disable state while said transfer flag signal is inputted.
3. A multimedia card comprising a flash memory, which includes a plurality of non-volatile memory cells to store data, and a controller for instructing operations of said non-volatile semiconductor memory based on an arbitrary one of commands issued from a host,
wherein said controller is provided with a process judging portion,
wherein said process judging portion is adapted to output a suspension signal when, during execution of a first command transferred from said host, a card selection signal for selecting said multimedia card transitions from an enable state to a disable state and storing of data to ones of said plurality of non-volatile memory cells has already started, and
wherein said controller executes said first command regardless of the state of said card selection signal and thereafter stays in a waiting condition before the data transfer when said process judging portion has output said suspension signal.
4. The multimedia card according to claim 3 , wherein said process judging portion comprises:
a command control unit that outputs an operation signal while said arbitrary one of the commands is executed; and
a process judging unit that receives an operation signal outputted from said command control unit, receives said card selection signal for selecting said multimedia card, and outputs said suspension signal when said card selection signal transitions from the enable state to the disable state while said operation signal is inputted.
5. The multimedia card according to claim 4 , wherein said command control unit outputs said operation signal when said controller executes an arbitrary one of a read command, a write command or an erase command.
6. A multimedia card comprising a flash memory including a plurality of non-volatile memory cells to store data and a controller for instructing operations of said non-volatile semiconductor memory based on a command issued from a host,
wherein said controller comprises:
a transfer control unit that detects that said host is transferring data and outputs a transfer flag signal;
a command control unit that outputs an operation signal during execution of the command issued by said host; and
a process judging unit that receives said transfer flag signal outputted from said transfer control unit, receives a card selection signal for selecting said multimedia card, and receives said operation signal output from said command control unit,
wherein said process judging unit is adapted to output an interruption signal when said card selection signal transitions from an enable state to a disable state while said transfer flag signal is in said enable state and before starting to store data to ones of said plurality of non-volatile memory cells, and is adapted to output a suspension signal when said card selection signal transitions from the enable state to the disable state while said operation signal is in said enable state and after starting to store data to ones of said plurality of non-volatile memory cells, and
wherein said controller is adapted to invalidate all data being transferred when said process judging unit outputs the interruption signal, and is adapted to execute said command regardless of the state of said card selection signal and thereafter to wait in a data waiting condition when said process judging unit outputs said suspension signal.
7. The multimedia card according to claim 6 , wherein said command control unit outputs said operation signal when said controller executes an arbitrary one of a read command, a write command or an erase command.