mc9s12e256 Freescale Semiconductor, Inc, mc9s12e256 Datasheet - Page 115

• Manufacturer Part Number: mc9s12e256
• Description: Hcs12 Microcontrollers 16-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

If the PVIOL flag is set in the FSTAT register, the user must clear the PVIOL flag before starting another
command write sequence (see
2.5
2.5.1
If a command is active (CCIF = 0) when the MCU enters wait mode, the active command and any buffered
command will be completed.
The Flash module can recover the MCU from wait mode if the CBEIF and CCIF interrupts are enabled
(Section 2.8,
2.5.2
If a command is active (CCIF = 0) when the MCU enters stop mode, the operation will be aborted and, if
the operation is program or erase, the Flash array data being programmed or erased may be corrupted and
the CCIF and ACCERR flags will be set. If active, the high voltage circuitry to the Flash memory will
immediately be switched off when entering stop mode. Upon exit from stop mode, the CBEIF flag is set
and any buffered command will not be launched. The ACCERR flag must be cleared before starting a
command write sequence (see
2.5.3
In background debug mode (BDM), the FPROT register is writable. If the MCU is unsecured, then all
Flash commands listed in
2.6
The Flash module provides the necessary security information to the MCU. After each reset, the Flash
module determines the security state of the MCU as defined in
(FSEC)”.
The contents of the Flash security byte at 0xFF0F in the Flash configuration field must be changed directly
by programming 0xFF0F when the MCU is unsecured and the higher address sector is unprotected. If the
Flash security byte remains in a secured state, any reset will cause the MCU to initialize to a secure
operating mode.
Freescale Semiconductor
Operating Modes
Flash Module Security
Wait Mode
Stop Mode
Background Debug Mode
“Interrupts”).
As active commands are immediately aborted when the MCU enters stop
mode, it is strongly recommended that the user does not use the STOP
instruction during program or erase operations.
Table 2-20
Section 2.3.2.7, “Flash Status Register
Section 2.4.1.2, “Command Write
MC9S12E256 Data Sheet, Rev. 1.08
can be executed.
NOTE
Section 2.3.2.2, “Flash Security Register
Sequence”).
Chapter 2 256 Kbyte Flash Module (FTS256K2V1)
(FSTAT)”).
115