Enhanced Interval Oscillator Training in Mobile DRAM

Recently, as the operating speed of mobile DRAM increases, the process of reliable transmission (Tx) and reception (Rx) between the DRAM and the controller, which is known as the training, becomes very important. In addition, the re-training is an important process that can compensate for the training delay variation caused by process, voltage, and temperature (PVT) variation that occurs frequently during mobile DRAM operation. In this paper, we propose the enhanced interval oscillator training method using time-digital convertor (TDC) for more accurate re-training than the conventional interval oscillator training.