250Khz clock using 328p with 16Mhz Crystal -- 2

Develop an arduino sketch for the Atmel 328P micro that can call a method like so: generateClockData(pointerToFirstBytes,NoBytes) Where NoBytes can be 3 or 4 bytes long. Details of how the method should behave... 1. Generate a continuous 250Khz clock output (50% Duty Cycle). 2. Generate a second serialized output synchronised to the rising edge of the above clock.. Details on second serialized synchronised output... 1. Read the start address of pointer passed into method. 2, Serialize all bits and bit-bang on second output pin allowing 3ms per byte, or 0.5ms on/off time per bit), but must synchronise the start of each bit to the rising edge of the Clock. Please use hardware modules on chip where necessary to reduce overhead. thats it!