Datasheet
Table Of Contents
- List of Sections
- Table of Contents
- General Description
- Central Processing Unit (CPU)
- Pinout and Signal Description
- System Configuration
- Registers
- Operating Modes
- Resource Mapping
- Bus Control and Input/Output
- Resets and Interrupts
- Voltage Regulator (VREG)
- Flash EEPROM 256K
- EEPROM 4K
- Port Integration Module
- Clocks and Reset Generator (CRG)
- Pulse Width Modulator (PWM)
- Enhanced Capture Timer (ECT)
- Serial Communications Interface (SCI)
- Serial Peripheral Interface (SPI)
- Inter-IC Bus (IIC)
- MSCAN
- Analog to Digital Converter
- Byte Data Link Controller Module
- Contents
- Overview
- Features
- Block Diagram
- Register Map
- Functional Description
- Register Descriptions
- External Pin Descriptions
- Reset Initialization/Basic Operation
- Transmitting A Message
- Receiving A Message
- Transmitting An In-Frame Response (IFR)
- Receiving An In-Frame Response (IFR)
- Special BDLC Operations
- Modes of Operation
- Interrupt Operation
- Low Power Options
- Background Debug Module (BDM)
- Breakpoint (BKP) Module
- Revision History
- Glossary
- Literature Updates

Central Processing Unit (CPU)
MC9S12DP256 — Revision 1.1
Central Processing Unit (CPU)
temporary storage of data. The stack pointer can also be used in all
indexed addressing modes.
Program counter is a 16-bit register that holds the address of the next
instruction to be executed. The program counter can be used in all
indexed addressing modes except autoincrement/decrement.
Condition Code Register (CCR) contains five status indicators, two
interrupt masking bits, and a STOP disable bit. The five flags are half
carry (H), negative (N), zero (Z), overflow (V), and carry/borrow (C). The
half-carry flag is used only for BCD arithmetic operations. The N, Z, V,
and C status bits allow for branching based on the results of a previous
operation.
Data Types
The STAR12 CPU supports the following data types:
• Bit data
• 8-bit and 16-bit signed and unsigned integers
• 16-bit unsigned fractions
• 16-bit addresses
A byte is eight bits wide and can be accessed at any byte location. A
word is composed of two consecutive bytes with the most significant
byte at the lower value address. There are no special requirements for
alignment of instructions or operands.
Freescale Semiconductor, I
Freescale Semiconductor, Inc.
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