Datasheet
• Flexmemory block contains up to 512KB FlexNVM and 16KB FlexRAM with up to 16KB EEPROM capability
• Up to 128KB SRAM
• 16KB cache
• Security circuitry to prevent unauthorized access to RAM and flash contents
4.5.3.2 External Bus Interface (FlexBus)
• Six independent, user-programmable chip-select signals that can interface with external SRAM, PROM, EPROM,
EEPROM, flash, and other peripherals
• Supports up to 2 GB addressable space
• 8-, 16- and 32-bit port sizes with configuration for multiplexed or non-multiplexed address and data buses
• Byte-, word-, longword-, and 16-byte line-sized transfers
• Programmable address-setup time with respect to the assertion of chip select
• Programmable address-hold time with respect to the negation of chip select and transfer direction
4.5.3.3 Serial Programming Interface (EzPort)
• Same serial interface as, and subset of, the command set used by industry-standard SPI flash memories
• Ability to read, erase, and program flash memory
• Reset command to boot the system after flash programming
4.5.3.4 NAND Flash Controller
• 8- and 16-bit NAND flash interface
• 9 KB RAM buffer
• Supports flash device commands
• Integrated DMA engine
• Two configurable DMA channels
• Optional ECC mode supports 4/6/8/12/16/24/32-bit error correction
Security and Integrity
4.5.4.1 Cyclic Redundancy Check (CRC)
• Hardware CRC generator circuit using 16/32-bit shift register
• User Configurable 16/32 bit CRC
• Programmable Generator Polynomial
• Error detection for all single, double, odd, and most multi-bit errors
• Programmable initial seed value
• High-speed CRC calculation
• Optional feature to transpose input data and CRC result via transpose register, required on applications where bytes are
in lsb format
4.5.4.2 Hardware Cryptographic Acceleration Unit (CAU)
• Supports DES, 3DES, AES, MD5, SHA-1, and SHA-256 algorithms
• Simple C calls to optimized security functions provided by Freescale
4.5.4
Security and Integrity
K20 Family Product Brief, Rev. 11, 08/2012
38 Freescale Semiconductor, Inc.