Datasheet

Flash EEPROM 256K
MC9S12DP256 — Revision 1.1
Flash EEPROM 256K
Banked Register A register operating on one flash block which shares the same register
address as the equivalent registers for the other flash blocks. The active
register bank is selected by two bank-select bits in the unbanked register
space.
Unbanked
Register
A register which operates on all flash blocks.
Command
Sequence
Three-step MCU instructions sequence to program or erase the Flash.
Overview
The 256K flash module is comprised of four 64K bytes blocks. They
serve as electrically erasable and programmable, non-volatile program
and data memory. The flash EEPROM is ideal for program and data
storage for single-chip applications allowing for field reprogramming
without requiring external programming voltage sources.
Each 64K byte flash block is arranged in a 32K by 16-bit configuration
and may be read as either bytes, aligned words or misaligned words.
Access time is one bus cycle for byte, and aligned word and two bus
cycles for misaligned word read. Write operations for program or erase
are only allowed as aligned word accesses. Each 64K block is organized
in 1024 rows of 32 words. An erase sector contains 8 rows or 512 bytes.
The erase mode supports erase sector as small as 512 bytes as well as
mass erase of each 64K byte block. An erased word reads $FFFF and
a programmed word reads $0000.
The programming voltage required to program and erase the flash is
generated internally by on-chip charge pumps. Program and erase
operations are performed by a command driven interface from the
microcontroller using an internal state machine. All flash blocks can be
programmed or erased at the same time, however it is not possible to
read from a flash block while it is being erased or programmed.
Freescale Semiconductor, I
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
nc...