Information

Table 29-4. EzPort status register field description (continued)
Field Description
6
WEF
Write error flag
Indicates whether there has been an error while executing a write command (SP, SE, BE, WRFCCOB, or
WRFLEXRAM). The WEF flag will set if Flash Access Error Flag (ACCERR), Flash Protection Violation
(FPVIOL), or Memory Controller Command Completion Status (MGSTAT0) inside the flash memory is set
at the completion of the write command. See the flash memory chapter for further description of these
flags and their sources. The WEF flag clears after a Read Status Register (RDSR) command.
0 = No error on previous write command.
1 = Error on previous write command.
7
FS
Flash security
Indicates whether the flash is secure. See Table 29-2 for the list of commands that will be accepted when
flash is secure. Flash security can be disabled by performing a BE command.
0 = Flash is not secure.
1 = Flash is secure.
29.3.1.4 Read Data
The Read Data (READ) command returns data from the flash memory or FlexNVM,
depending on the initial address specified in the command word. The initial address must
be 32-bit aligned with the two LSBs being zero.
Data continues being returned for as long as the EzPort chip select (
EZP_CS) is asserted,
with the address automatically incrementing. In this way, the entire contents of flash can
be returned by one command. Attempts to read from an address which does not fall
within the valid address range for the flash memory regions returns unknown data. See
Flash memory map for EzPort access.
For this command to return the correct data, the EzPort clock (EZP_CK) must run at the
internal system clock divided by eight or slower. This command is not accepted if the
WEF, WIP, or FS field in the EzPort status register is set.
29.3.1.5 Read Data at High Speed
The Read Data at High Speed (FAST_READ) command is identical to the READ
command, except for the inclusion of a dummy byte following the address bytes and
before the first data byte is returned.
This command can be run with an EzPort clock (EZP_CK) frequency of half the internal
system clock frequency of the microcontroller or slower. This command is not accepted if
the WEF, WIP, or FS field in the EzPort status register is set.
Chapter 29 EzPort
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 563