Data rate supply proportional to the ratio of different printhead lengths

1. A printer controller configured to generate dot data for supply to a pagewidth printhead which includes at least a first printhead integrated circuit and a second printhead integrated circuit arranged adjacent each other either side of a join region, the first and second printhead integrated circuits having different lengths which aggregate in said adjacent arrangement so that the first and second printhead integrated circuits extend across said pagewidth, the printer controller configured to transfer dot data to each of the first and second printhead integrated circuits at a rate proportional to the relative lengths of the first and second printhead integrated circuits so that the dot data is transferred to each of the first and second printhead intergated circuits in equal time.

2. The printer controller as claimed in claim 1 , wherein the printer controller includes a printhead interface in communication with a line loader unit.

3. The printer controller as claimed in claim 2 , wherein the printhead interface transfers the dot data to the first printhead integrated circuit and the second printhead integrated circuit at a pre-programmed rate.

4. The printer controller as claimed in claim 1 , wherein the dot data transfer rate is controlled by at least one register.

5. The printer controller as claimed in claim 4 , wherein there is provided one register per printhead integrated circuit.

6. The printer controller as claimed in claim 1 , wherein the dot data transfer rate can be varied between 0 to 100% of maximum capacity.

7. The printer controller as claimed in claim 2 , wherein the printhead interface accepts two streams of dot data from the line loader unit.

8. The printer controller as claimed in claim 7 , wherein the line loader unit includes two dot data generator units.

9. The printer controller as claimed in claim 2 , wherein the line loader unit compensates for any vertical misalignment between the first printhead integrated circuit and the second printhead integrated circuit.

10. The printer controller as claimed in claim 2 , wherein the line loader unit generates dot data at a rate of at least 12 bits per cycle, where a cycle is the system clock period.

11. The printer controller as claimed in claim 1 , wherein the dot data is transferred to either the first printhead integrated circuit or the second printhead integrated circuit from a memory under the control of the printhead controller.

12. The printer controller as claimed in claim 1 , configured to manipulate the supply of dot data to each of the printhead integrated circuits such that usage of a memory bandwidth is substantially constant during a printhead loading cycle.