Means for reducing direct memory access

A method of reducing direct memory access in a machine employing a data segmenting scheme, comprising the steps of:

• a. detecting when a repetitive block of data is to be transferred, wherein the repetitive block of data repeats a data word of a predetermined value for a predetermined number of repetitions;
• b. if a repetitive block of data is to be transferred,
• then assigning a first invalid address to a next segment pointer, the first invalid address indicating that the repetitive block of data is to be generated after a transfer of a first data segment is complete,
• otherwise assigning a first memory address of a second data segment to the next segment pointer;
• c. when transfer of the first data segment is complete, assigning to a current address pointer a value currently assigned to the next segment pointer;
• d. while the value assigned to the current address pointer corresponds to a valid memory address, performing the following steps:
• i. assigning to an end segment pointer a value corresponding to a last memory address of a second data segment;
• and
• ii. while the value assigned to the current address pointer is not equal to the value assigned to the end segment pointer, performing the following steps:
• A. accessing a memory location addressed at the value assigned to the current address pointer;
• B. fetching a data word stored in the memory location;
• and
• C. stepping the value assigned to the current address pointer;
• and
• e. while the value assigned to the current address pointer corresponds to an invalid memory address, performing the following steps:
• i. assigning to an end segment pointer a value corresponding to the value assigned to the current address pointer plus a value corresponding to the predetermined number of repetitions;
• and
• ii. while the value assigned to the current address pointer is not equal to the value assigned to the end segment pointer, performing the following steps:
• A. generating a data word of a predetermined type;
• and
• B. stepping the value assigned to the current address pointer.

A printer, comprising:

• a. a printer controller that includes a digital control circuit programmed to execute the following operations:
• i. detect when a repetitive block of data is to be printed, wherein the repetitive block of data repeats a data word of a predetermined value;
• ii. assign a first invalid address to a next segment pointer, the first invalid address indicating that the repetitive block of data is to be generated after a transfer of a current segment is complete;
• iii. assign a second invalid address to an end segment pointer, the second invalid address corresponding to the first invalid address plus a value indicating a number of repetitive data words that is included in the block of repetitive data;
• iv. assign the first invalid address to a current address pointer;
• and
• v. while the current address pointer has a value assigned thereto that is not equal to the second invalid address, performing the following steps:
• A. generate a data word of the predetermined value;
• and
• B. step the value assigned to the current pointer;
• and
• b. a printer mechanism that receives the data word of the predetermined value from the printer controller and that executes a print operation corresponding to the data word of predetermined value.

An apparatus for reducing direct memory access in a machine employing a data segmenting scheme, comprising:

• a. means for detecting a repetitive block of data that is to be transferred, wherein the repetitive block of data repeats a data word of a predetermined value;
• b. means for assigning a first invalid address to a first pointer, the first invalid address indicating that the repetitive block of data is to be generated after a transfer of a current segment is complete;
• c. means for assigning a second invalid address to a second pointer, the second invalid address corresponding to the first invalid address plus a value indicating a number of repetitive data words that is included in the block of repetitive data;
• d. means for assigning the first invalid address to a third pointer;
• e. means for generating a data word of the predetermined value while the third pointer has a value assigned that is less than the second invalid address;
• and
• f. means for stepping the value assigned to the third pointer while the third pointer has a value assigned that is less than the second invalid address.