This paper presents the design and implementation of a new parallel Algorithmic Pattern Generator (ALPG) of Automatic Test Equipment (ATE) for the high speed memory testing. We implemented the Instruction Analyzer (IA) that unrolls the instructions using simple instructions. And, unrolled instruction memory is also implemented to reduce the delay of the IA. These implementations allow the ALPG to operate flexible algorithms at high speed. For high speed, we also designed the ALPG of multiple Pattern Generators (PG) with phase-shifting clocks. Therefore, the ALPG has expandability and operates at high speed with the high flexibility of the algorithms.