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

Flash EEPROM 256K
Register Descriptions
MC9S12DP256 — Revision 1.1
Flash EEPROM 256K
FSEC Ñ Flash
Security Register
Read: Anytime
Write: Never
This register is unbanked. It holds all bits associated with the device
security. This register is loaded from flash address $FF0F during the
reset sequence, indicated by “F” in the reset row of the register
description.
KEYEN — Enable backdoor key to security
1 = Backdoor to flash read via BDM or external bus interface is
enabled
0 = Backdoor to flash read via BDM or external bus interface is
disabled
Table 29 Example FCLKDIV settings
Oscillator
Frequency
PRDIV8 FDIV[5:0]
FCLK
Frequency
FCLK
Period
1.0MHz 0 000100 200KHz 5us
2.0MHz 0 001001 200KHz 5us
4.0MHz 0 010011 200KHz 5us
8.0MHz 0 100111 200KHz 5us
16.0MHz 1 001001 200KHz 5us
Address Offset: $0001
Bit 7 654321Bit 0
Read: KEYEN NV6 NV5 NV4 NV3 NV2 SEC01 SEC00
Write:
Reset: FFFFFFFF
= Reserved or unimplemented
Freescale Semiconductor, I
Freescale Semiconductor, Inc.
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