MC908KX2MDWE Datasheet, PDF (195/210 Pages) Freescale Semiconductor, Inc – High-performance M68HC08 architecture, Fully upward-compatible object code with M6805, M146805, and M68HC05 Families

Appendix A
MC68HC908KX2
A.1 Introduction
This appendix describes the differences between the MC68HC908KX8 and the MC68HC908KX2.
A.2 Functional Description
The MC68HC908KX2 FLASH memory is an array of 2,048 bytes with an additional 36 bytes of user
vectors and one byte used for block protection. See Figure A-1.
NOTE
An erased bit reads as a 1 and a programmed bit reads as a 0.
The program and erase operations are facilitated through control bits in the FLASH control register
(FLCR). See 2.6 FLASH Control Register.
The FLASH is organized internally as an 8-word by 8-bit complementary metal-oxide semiconductor
(CMOS) page erase, byte (8-bit) program embedded FLASH memory. Each page consists of 64 bytes.
The page erase operation erases all words within a page. A page is composed of two adjacent rows.
A security feature prevents viewing of the FLASH contents.⁽¹⁾
See 2.6 FLASH Control Register for a complete description of FLASH operation.
1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the FLASH difficult for
unauthorized users.
MC68HC908KX8 • MC68HC908KX2 • MC68HC08KX8 Data Sheet, Rev. 2.1
Freescale Semiconductor
195