  Channel output quantization plays a vital role in high-speed emerging
memories such as the spin-torque transfer magnetic random access memory
(STT-MRAM), where high-precision analog-to-digital converters (ADCs) are not
applicable. In this paper, we investigate the design of the 1-bit quantizer
which is highly suitable for practical applications. We first propose a
quantized channel model for STT-MRAM. We then analyze various information
theoretic bounds for the quantized channel, including the channel capacity,
cutoff rate, and the Polyanskiy-Poor-Verd\'{u} (PPV) finite-length performance
bound. By using these channel measurements as criteria, we design and optimize
the 1-bit quantizer numerically for the STT-MRAM channel. Simulation results
show that the proposed quantizers significantly outperform the conventional
minimum mean-squared error (MMSE) based Lloyd-Max quantizer, and can approach
the performance of the 1-bit quantizer optimized by error rate simulations.
