OVERVIEW
This manual includes hardware details and programming information for the MC68HC000, the MC68HC001, the MC68EC000, and the MC68SEC000. For ease of reading, the name M68000 MPUs will be used when  referring to all processors. Refer to M68000PM/AD, M68000 Programmers Reference Manual, for detailed  information on the MC68000 instruction set.

The four microprocessors are very similar to each other and all contain the following features:
• Sixteen 32-Bit Data and Address Registers
• 16-Mbyte Direct Addressing Range
• Program Counter
• 6 Instruction Types
• Operations on Five Main Data Types
• Memory-Mapped Input/Output (I/O)
• 14 Addressing Modes

The following processors contain additional features:
• MC68HC001/MC68EC000/MC68SEC000
   — Statically selectable 8- or 16-bit data bus
• MC68HC000/MC68EC000/MC68HC001/MC68SEC000
   — Low power

The primary features of the MC68SEC000 embedded processor include the following:
• Direct Replacement for the MC68EC000
   — Pin-for-pin compatibility with the MC68EC000 in the plastic QFP and TQFP packages
   — Vast selection of existing third-party development tools for the MC68EC000 support the  MC68SEC000
   — Software written for the MC68EC000 will run unchanged on the MC68SEC000
• Power Management
   — Low-power HCMOS technology
   — Static design allows for stopping the processor clock
   — 3.3V or 5V operation
   — Typical 0.5µA current consumption at 3.3V in sleep mode
• Software Strength
   — Fully upward object-code compatible with other M68000 Family products  
   — M68000 architecture allows effective assembly code with a C compiler
• Upgrade
   — Fully upward code-compatible with higher performance 680x0 and 68300 Family members
   — ColdFire® code-compatible with minor modifications