Universal controller interface for barcode printers

A controller interface for use in any one of a plurality of barcode printers between a processor of the printer and a number of the printer's input and output devices including a printhead, said controller comprising:

• a printhead control interface for allowing said controller to communicate with a thermal printhead of a first type or a thermal printhead of a different, second type, said printhead control interface generating a first set of printhead control signals on a plurality of output control lines for a thermal printhead of said first type and said printhead control interface generating a second set of printhead control signals on less than all of said output control lines for a thermal printhead of said second type.

A controller interface for use in any one of a plurality of barcode printers between a processor of the printer and a number of the printer's input and output devices including a printhead, said controller comprising:

• a serial input/output port for shifting serial data out from said controller or for shifting serial data into said controller, said data including a most significant bit and a least significant bit;
• and said serial input/output port being programmable to determine the number of bits to be shifted, whether data is to be shifted in or to be shifted out and to determine whether said most significant bit or said least significant bit is to be shifted first.

A controller interface for use in any one of a plurality barcode printers between a processor of the printer and a number of the printer's input and output devices including a printhead, said controller comprising:

• a baud rate generator for generating each output clock pulse from a plurality of input clock pulses in a predetermined pattern, said baud rate generator being programmable to accept input clock pulses at a plurality of different frequencies, each input frequency having a different associated clock pulse pattern for generating output clock pulses at a desired frequency.

A controller interface for use in any one of a plurality of barcode printers between a processor of the printer and a number of the printer's input and output devices including a printhead, said printer's processor having an associated memory that can be written to and read from and said controller comprising:

• memory protection means for preventing a user from writing into an area of said memory to be protected wherein said memory protection means includes a programmable register for storing information representing a range of addresses in said memory defining the area of said memory to be protected and means for comparing a write address defining a location of said memory to be written to with said stored range of addresses, said comparing means preventing information from being written to said location in said memory if said write address is within said range of addresses represented by information stored in said programmable register.