PC912XDP512F0MPVR datasheet(1143/1348 Pages) FREESCALE

1143 / 1348 page

Chapter 27 512 Kbyte Flash Module (S12XFTX512K4V2)

MC9S12XDP512 Data Sheet, Rev. 2.21

Freescale Semiconductor

1145

If the PVIOL ﬂag is set in the FSTAT register, the user must clear the PVIOL ﬂag before starting another

command write sequence (see Section 27.3.2.6, “Flash Status Register (FSTAT)”).

27.5

Operating Modes

27.5.1

Wait Mode

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

(see Section 27.8, “Interrupts”).

27.5.2

Stop Mode

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 Section 27.4.1.2, “Command Write Sequence”).

NOTE

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.

27.5.3

Background Debug Mode

In background debug mode (BDM), the FPROT register is writable. If the MCU is unsecured, then all

Flash commands listed in Table 27-20 can be executed. If the MCU is secured and is in special single chip

mode, only mass erase can be executed.

27.6

Flash Module Security

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 Section 27.3.2.2, “Flash Security Register

(FSEC)”.

The contents of the Flash security byte at 0x7F_FF0F in the Flash Conﬁguration Field must be changed

directly by programming 0x7F_FF0F when the MCU is unsecured and the higher address sector is

unprotected. If the Flash security byte is left in a secured state, any reset will cause the MCU to initialize

to a secure operating mode.

PC912XDP512F0MPVR 데이터시트(PDF) 1143 Page - Freescale Semiconductor, Inc