This invention discloses 2D or 3D NAND flash array in two-level BL-hierarchical structure with flexible multi-page or random-page-based concurrent, mixed SLC and MLC Read, Program or Program-Verify operations including bit-flipping for each program state or any combinations of above operations. Tracking techniques of self-timed control and algorithm of programming, read and local-bit line (LBL) voltage generations are proposed for enhancing automatic controls over charging and discharging of a plurality of WLs and LBLs in one or more randomly selected Blocks in one or more Segments of one or more Groups in a NAND plane for m-page concurrent operations using Vdd/Vss to Vinh/Vss Program page data conversion, multiple pseudo CACHEs based on LBL capacitors for storing raw SLC and MSB/LSB loaded page data, writing back or reading from Sense-Amplifier, Program/Read Buffer, real CHCHE, and multiple pseudo CACHEs with M-fold reduction in latency and power consumption.