Flash memoryMPC5644A Microcontroller Reference Manual, Rev. 6Freescale Semiconductor 217Chapter 12Flash memory12.1 IntroductionThis section presents information about the following components on this device:• The flash memory blocks• The platform flash memory controllerThe primary function of the flash memory module is to serve as electrically programmable and erasablenon-volatile memory. The NVM memory can be used for instruction and data storage. The block is anon-volatile solid-state silicon memory device consisting of blocks of single-transistor storage elements,an electrical means for selectively adding (programming) and removing (erasing) charge from theseelements, and a means of selectively sensing (reading) the charge stored in these elements. The flash isaddressable by word (32 bits) and page (128 bits).There are two flash array blocks (Flash_A and Flash_B). Within each flash block are two functional units:the flash core (FC) and the memory interface (MI).The FC is composed of arrayed non-volatile storage elements, sense amplifiers, row selects, columnselects, charge pumps, and redundancy logic. The arrayed storage elements in the FC are subdivided intophysically separate units referred to as blocks.The MI contains the registers and logic which control the operation of the FC. The MI is also the interfaceto the platform flash bus interface unit (PFBIU).The flash array’s core has three address spaces: low-address space, mid-address space, and high-addressspace (see Figure 12-1).
