Information

Flash Operation in Low-Power Modes
28.4.4.1 Wait Mode
When the MCU enters wait mode, the flash memory module is not affected. The flash
memory module can recover the MCU from wait via the command complete interrupt
(see Interrupts).
28.4.4.2 Stop Mode
When the MCU requests stop mode, if a flash command is active (CCIF = 0) the
command execution completes before the MCU is allowed to enter stop mode.
CAUTION
The MCU should never enter stop mode while any flash
command is running (CCIF = 0).
NOTE
While the MCU is in very-low-power modes (VLPR, VLPW,
VLPS), the flash memory module does not accept flash
commands.
28.4.5 Functional Modes of Operation
The flash memory module has two operating modes: NVM Normal and NVM Special.
The operating mode affects the command set availability (see Table 28-31). Refer to the
Chip Configuration details of this device for how to activate each mode.
28.4.6 Flash Reads and Ignored Writes
The flash memory module requires only the flash address to execute a flash memory
read. MCU read access is available to all flash blocks.
The MCU must not read from the flash memory while commands are running (as
evidenced by CCIF=0) on that block. Read data cannot be guaranteed from a flash block
while any command is processing within that block. The block arbitration logic detects
any simultaneous access and reports this as a read collision error (see the
FSTAT[RDCOLERR] bit).
28.4.4
Chapter 28 Flash Memory Module (FTFL)
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 525