Motorola MPC533 Reference Manual page 824

eight large blocks, two of which contain small blocks. Information is transferred to the
UC3F EEPROM by long-word (64 bits), word (32 bits), half-word (16 bits), or byte (8 bits).
To improve system performance, each array read access retrieves 32 bytes of information.
These 32 bytes may be copied into one of two read page buffers aligned to the low order
addresses. The two read page buffers are independently updated by page management logic
contained in the BIU which interfaces to the UC3F EEPROM module.
To prevent unnecessary page accesses from the array, the UC3F memory interface (MI)
monitors the incoming address to determine if the required information is in one of the two
read page buffers. This strategy allows the UC3F array to have an off page access and an
on page access. In normal operation, write accesses to the UC3F array are not recognized
except during program and erase operations.
The UC3F EEPROM uses an embedded hardware algorithm to program and erase the
UC3F array. Special control logic is included to guard against accidental program or erase
by requiring a specific series of read and write accesses to the UC3F control registers.
External inputs provide a hardware protection mechanism to prevent accidental program
and erase of UC3F array blocks. The hardware algorithm automatically performs all
necessary applications of high voltage pulses and verify reads of the UC3F array to ensure
that all bits are programmed and erased with sufficient margin to guarantee data integrity
and reliability.
19.0.1 Features of the CDR3 Flash EEPROM (UC3F)
• High density single transistor Flash bit cell
• -40 to 125° C ambient temperature operating range
— -40 to 85° C on the suffix C device
• 2.5-V to 2.7-V V
• Shadow information stored in special Flash NVM shadow locations
• 512 Kbytes using 64-Kbyte blocks
— Two 16-Kbyte small blocks
• Array block restriction control for small and large blocks
— Erase by array blocks
— Array protection for program and erase operations
— Array block assignment of supervisor or supervisor/user space
— Array block assignment of data or instruction/data space
• Internal 64-bit data path architecture
• Page mode read
— Retains two independent read page buffers
— Read page size of 32 bytes (8 words).
19-2
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
operating range and 4.75-V to 5.25-V V
DDF
MPC533 Reference Manual
operating range
FLASH
MOTOROLA