US 11,726,747 B2
Magnetoresistive random-access memory (MRAM) random number generator (RNG) and a related method for generating a random bit
Harry-Hak-Lay Chuang, Zhubei (TW); Chih-Yang Chang, Hsinchu (TW); Ching-Huang Wang, Pingjhen (TW); Chih-Hui Weng, Tainan (TW); Tien-Wei Chiang, Taipei (TW); Meng-Chun Shih, Hsinchu (TW); Chia Yu Wang, Hsinchu County (TW); and Chia-Hsiang Chen, Hsinchu (TW)
Assigned to Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu (TW)
Filed by Taiwan Semiconductor Manufacturing Company, Ltd., Hsin-Chu (TW)
Filed on Dec. 9, 2022, as Appl. No. 18/78,482.
Application 18/078,482 is a continuation of application No. 16/434,345, filed on Jun. 7, 2019, granted, now 11,531,524.
Claims priority of provisional application 62/735,292, filed on Sep. 24, 2018.
Prior Publication US 2023/0115281 A1, Apr. 13, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. G06F 7/58 (2006.01); G11C 11/16 (2006.01)
CPC G06F 7/588 (2013.01) [G11C 11/1673 (2013.01); G11C 11/1675 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for generating a random bit, the method comprising:
generating a random bit by providing a random number generator (RNG) signal to a magnetoresistive random-access memory (MRAM) cell, wherein the RNG signal has a RNG value of a write parameter, which results in the MRAM cell switching from a first resistive state to a second resistive state with a probability of about 0.5; and
determining the RNG value, comprising:
repeatedly providing a first write signal having a first write value of the write parameter to the MRAM cell;
repeatedly providing a second write signal having a second write value of the write parameter to the MRAM cell, wherein the second write value is different than the first write value;
determining the RNG value to be the first write value in response to the first write signal switching the MRAM cell from the first resistive state to the second resistive state with the probability of about 0.5; and
determining the RNG value to be the second write value in response to the second write signal switching the MRAM cell from the first resistive state to the second resistive state with the probability of about 0.5.