Information

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 FlexRAM
can be returned by one command.
The initial address must be 32-bit aligned (the two LSBs must be zero). Attempts to read
from an address which does not fall within the valid address range for the FlexRAM
returns unknown data. See Flash memory map for EzPort access for more information.
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 fields in the EzPort status register are set.
29.3.1.14 Read FlexRAM at High Speed
The Read FlexRAM at High Speed (FAST_RDFLEXRAM) command is identical to the
RDFLEXRAM 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 up to and including
half the internal system clock frequency of the microcontroller. This command is not
accepted if the WEF, WIP, or FS fields in the EzPort status register are set.
29.4 Flash memory map for EzPort access
The following table shows the flash memory map for access through EzPort.
NOTE
The flash block address map for access through EzPort may not
conform to the system memory map. Changes are made to
allow the EzPort address width to remain 24 bits.
Table 29-5. Flash Memory Map for EzPort Access
Valid start address Size Flash block Valid commands
0x0000_0000
See device's chip
configuration details
Flash READ, FAST_READ, SP, SE, BE
0x0080_0000
See device's chip
configuration details
FlexNVM READ, FAST_READ, SP, SE, BE
0x0000_0000
See device's chip
configuration details
FlexRAM
RDFLEXRAM, FAST_RDFLEXRAM,
WRFLEXRAM, BE
Chapter 29 EzPort
K20 Sub-Family Reference Manual, Rev. 2, Feb 2012
Freescale Semiconductor, Inc. 569