HCS12 datasheet(27/452 Pages) FREESCALE

27 / 452 page

S12CPUV2 Reference Manual, Rev. 4.0

Freescale Semiconductor

operations. Shift and rotate instructions operate through the C bit to facilitate

multiple-word shifts.

2.3 Data Types

The CPU12 uses these types of data:

• Bits

• 5-bit signed integers

• 8-bit signed and unsigned integers

• 8-bit, 2-digit binary-coded decimal numbers

• 9-bit signed integers

• 16-bit signed and unsigned integers

• 16-bit effective addresses

• 32-bit signed and unsigned integers

Negative integers are represented in two’s complement form.

Five-bit and 9-bit signed integers are used only as offsets for indexed

addressing modes.

Sixteen-bit effective addresses are formed during addressing mode

computations.

Thirty-two-bit integer dividends are used by extended division instructions.

Extended multiply and extended multiply-and-accumulate instructions

produce 32-bit products.

2.4 Memory Organization

The standard CPU12 address space is 64 Kbytes. Some M68HC12 devices

support a paged memory expansion scheme that increases the standard

space by means of predefined windows in address space. The CPU12 has

special instructions that support use of expanded memory.

Eight-bit values can be stored at any odd or even byte address in available

memory.

HCS12 Datasheet(PDF) 27 Page - Freescale Semiconductor, Inc