Embedded memories form a crucial part in the design of modern high performance microprocessors. The number of transistors in memories form a majority of the transistors in a typical high performance microprocessor. Therefore, modeling embedded memories is an important challenge in high performance microprocessor design. A typical design process involves a multiplicity of interacting methodologies - simulation, formal verification, design for test, emulation etc. Memory models are needed for each of these methodologies. This complicates the process of modeling memories. We present a tool called MemGen that automates memory model generation for all methodologies. It has been used in-house in Motorola Inc. and then later in Freescale Semiconductor Inc. in all high performance design projects. We present results obtained by using MemGen-generated embedded memories in real life design projects of PowerPC^1 G2 and G4 microprocessors.