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Chapter 19 128 KB Flash Module (S12ZFTMRZ128K512V2)
MC9S12ZVM Family Reference Manual Rev. 1.3
Freescale Semiconductor
737
19.4.8.1
Description of Flash Interrupt Operation
The Flash module uses the CCIF flag in combination with the CCIE interrupt enable bit to generate the
Flash command interrupt request. The Flash module uses the SFDIF flag in combination with the SFDIE
interrupt enable bits to generate the Flash error interrupt request. For a detailed description of the register
bits involved, refer to
Section 19.3.2.5, “Flash Configuration Register (FCNFG)
Error Configuration Register (FERCNFG)
Section 19.3.2.7, “Flash Status Register (FSTAT)
Section 19.3.2.8, “Flash Error Status Register (FERSTAT)
The logic used for generating the Flash module interrupts is shown in
Figure 19-31. Flash Module Interrupts Implementation
19.4.9
Wait Mode
The Flash module is not affected if the MCU enters wait mode. The Flash module can recover the MCU
from wait via the CCIF interrupt (see
).
19.4.10 Stop Mode
If a Flash command is active (CCIF = 0) when the MCU requests stop mode, the current Flash operation
will be completed before the MCU is allowed to enter stop mode.
19.5
Security
The Flash module provides security information to the MCU. The Flash security state is defined by the
SEC bits of the FSEC register (see
). During reset, the Flash module initializes the FSEC
register using data read from the security byte of the Flash configuration field at global address
0xFF_FE0F. The security state out of reset can be permanently changed by programming the security byte
assuming that the MCU is starting from a mode where the necessary P-Flash erase and program commands
are available and that the upper region of the P-Flash is unprotected. If the Flash security byte is
successfully programmed, its new value will take affect after the next MCU reset.
The following subsections describe these security-related subjects:
•
Unsecuring the MCU using Backdoor Key Access
•
Unsecuring the MCU in Special Single Chip Mode using BDM
Flash Error Interrupt Request
CCIF
CCIE
SFDIF
SFDIE
Flash Command Interrupt Request