The MX25L6433FM2I-08G is a 64Mbit (8MB) SPI NOR Flash from Macronix in SOIC-16 (300mil), supporting standard SPI, Dual SPI, and Quad SPI interfaces at clock rates up to 133MHz. In Quad SPI mode, all four data lines (IO0-IO3) transfer data simultaneously, achieving 4x throughput (532Mbps effective) for fast boot and code shadowing. Memory organization: 128 sectors of 64KB, each sector containing 256 pages of 256 bytes. Program operations: Page Program (PP) writes up to 256 bytes in 0.7ms typical. Quad Page Program (QPP) accepts data on all 4 IO pins for faster programming. Sector Erase takes 200ms, Block Erase (32KB) 150ms, Chip Erase 80s. The 4KB sub-sector erase enables fine-grained updates. Security features include: one-time programmable (OTP) area for serial numbers, 3×256-byte security registers with 64-bit unique ID, and individual block locking. The -08G speed grade specifies 133MHz clock and 8ns hold time. The -I suffix denotes industrial temperature range (-40C to +85C). Deep power-down mode reduces current to 5uA. Endurance is 100,000 cycles per sector with 20-year data retention.