Access to printing material container

A plurality of non-volatile storage devices, each connecting with a control unit via a bus with a clock terminal, a data terminal, and a reset terminal, said control unit comprising a clock signal generation circuit that generates a clock signal, a reset signal generation circuit that generates a reset signal, an identification information output circuit that outputs identification information to identify a desired storage device among said plurality of storage devices, and a data output circuit that transmits a data array including the output identification information and a write/read command to a data signal line synchronously with the clock signal,

• each of said storage devices comprising:
• a data bus that connects with the data terminal;
• a storage element that has a storage area sequentially accessed;
• a comparator that connects with the data bus and compares the identification information output via the identification information output circuit and the data output circuit of said control unit with identification information stored in the storage element to determine coincidence or incoincidence of the two pieces of identification information;
• an input-output controller that is interposed between the storage element and the data bus and controls a direction of data transfer with regard to the storage element as well as a direction of data transfer with regard to the data bus;
• and
• a command decoder that connects with the data bus and the comparator, analyzes the write/read command input via the data bus when a result of the determination by the comparator represents coincidence of the identification information output from said control unit with the identification information stored in the storage element, and requires the input-output controller to switch over the direction of data transfer with regard to the data bus based on a result of the analysis.

A non-volatile storage device that connects with a clock signal line, a data signal line, and a reset signal line and is detachably attached to a printing material container, said storage device comprising:

• a storage element that has a non-volatile storage area and is subjected to a writing/reading operation based on a clock signal input via the clock signal line and a data signal input and output via the data signal line;
• a comparator that compares printing material container identification information, which is included in the data signal and assigned to said printing material container for identification thereof, with identification information stored in advance in the storage element to determine coincidence or incoincidence of the two pieces of identification information;
• and
• an input-output controller that allows the writing/reading operation into and from the storage element when the comparator determines coincidence of the two pieces of identification information.

A method of gaining access to a desired storage device among a plurality of non-volatile storage devices, each storage device connecting with a clock signal line, a data signal line, and a reset signal line via a bus and storing proper identification information therein,

• said method comprising the steps of:
• outputting a reset signal to the reset signal line;
• and
• transmitting a data array including identification information, which is assigned to said desired storage device to be accessed, and a write/read command to the data signal line synchronously with a clock signal.

A method of processing an access requirement in a storage device, said storage device having a storage element that includes a storage area sequentially accessed and a specific section between a head position and a predetermined position of the storage area to store identification information therein, said storage device sharing a clock bus that is connected to a clock signal line, a data bus that is connected to a data signal line, and a reset bus that is connected to a reset signal line with another storage device,

• said method comprising the steps of:
• resetting a count on an address counter to an initial value in response to detection of a reset signal on the reset bus;
• comparing identification information transmitted to the data bus with the identification information stored in the storage element to determine coincidence or incoincidence of the two pieces of identification information;
• when the result of the determination represents coincidence of the identification information transmitted to the data bus with the identification information stored in the storage element, analyzing a write/read command transmitted to the data bus;
• controlling data transfer with regard to the data bus and data transfer with regard to the storage element based on the result of the analysis;
• and
• carrying out either one of an operation of writing data at a desired position in the storage element and an operation of reading data from the storage element, based on the count on the address counter.

In a non-volatile storage device having a storage element sequentially accessed, a method of storing identification information in a specific section located between a head position and a predetermined position of a storage area in the storage element,

• said method comprising the steps of:
• resetting a count on an address counter to an initial value and prohibiting increment of the count synchronously with a clock signal, in response to detection of a reset signal;
• setting a direction of data transfer with regard to a data bus to a writing direction and a direction of data transfer with regard to the storage element to a writing direction, in response to a write command transmitted to the data bus;
• allowing increment of the count on the address counter synchronously with the clock signal after completion of the settings of the directions of data transfer;
• and
• writing the identification information between the head position and the predetermined position of the storage area in the storage element and subsequently writing data into the storage area according to the count on the address counter.

In a non-volatile storage device having a storage element sequentially accessed, a method of reading data stored in a storage area of the storage element from a head position of the storage area,

• said method comprising the steps of:
• resetting a count on an address counter to an initial value and prohibiting increment of the count synchronously with a clock signal, in response to detection of a reset signal;
• setting a direction of data transfer with regard to a data bus to a reading direction and a direction of data transfer with regard to the storage element to a reading direction, in response to a read command transmitted to the data bus;
• allowing increment of the count on the address counter synchronously with the clock signal after completion of the settings of the directions of data transfer;
• and
• reading data stored in the storage area of the storage element from the head position of the storage area according to the count on the address counter.

In a non-volatile storage device having a storage element sequentially accessed, a method of storing identification information in a specific section located between a head position and a predetermined position of a storage area in the storage element,

• said method comprising the steps of:
• carrying out retrieval to find a piece of identification information that coincides with the identification information stored in the storage element of said storage device;
• when the piece of identification information that coincides with the identification information stored in the storage element is found, transmitting the piece of identification information and a write command to said storage device;
• transmitting a data array to said storage device, the data array including the identification information after data corresponding to an end position of the storage area in the storage element of said storage device;
• and
• writing data up to the end position of the storage area in the storage element and subsequently writing the identification information from the head position to the predetermined position of the storage area in the storage element, according to a count on an address counter.