mcf51jf128 Freescale Semiconductor, Inc, mcf51jf128 Datasheet - Page 583

• Manufacturer Part Number: mcf51jf128
• Description: Mcf51jf128 Reference Manual
• Manufacturer: Freescale Semiconductor, Inc

25.3.1.4 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 (the two LSBs must be 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 (see
memory regions returns junk data.
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 bit in the EzPort status register is set.
25.3.1.5 Read Data at High Speed
The Read Data at High Speed command (FAST_READ) 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 micro-controller or slower. This command is not accepted
if the WEF, WIP, or FS bit in the EzPort status register is set.
Freescale Semiconductor, Inc.
6
WEF
7
FS
Field
Table 25-4. EzPort Status Register Field Descriptions (continued)
Write error flag
Status flag that indicates if there has been an error while executing a write command (SP, SE, BE,
WRFCCOB, or WRFLEXRAM). The WEF flag will set if either the Flash Access Error Flag (ACCERR) or
the Flash Protection Violation Flag (FPVIOL) or the Memory Controller Command Completion Status Flag
(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.
Flash security
Status flag that indicates if the flash is secure. See
accepted when flash is secure. Flash security can be disabled by performing a Bulk Erase (BE) command.
0 = Flash is not secure
1 = Flash is secure.
MCF51JF128 Reference Manual, Rev. 2, 03/2011
Flash Memory Map for EzPort
Preliminary
Description
Table 25-2
for the list of commands which will be
Access) for the flash
Chapter 25 EzPort
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