Chapter 21 64 KB Flash Module (S12ZFTMRZ64K2KV2)
S12ZVHY/S12ZVHL Family Reference Manual Rev. 1.05
Freescale Semiconductor
721
21.4.6
Allowed Simultaneous P-Flash and EEPROM Operations
Only the operations marked ‘OK’ in
are permitted to be run simultaneously on the Program
Flash and EEPROM blocks. Some operations cannot be executed simultaneously because certain
hardware resources are shared by the two memories. The priority has been placed on permitting Program
Flash reads while program and erase operations execute on the EEPROM, providing read (P-Flash) while
write (EEPROM) functionality. Any attempt to access P-Flash and EEPROM simultaneously when it is
not allowed will result in an illegal access that will trigger a machine exception in the CPU (please look
into the Reference Manual for details). Please note that during the execution of each command there is a
period, before the operation in the Flash array actually starts, where reading is allowed and valid data is
returned. Even if the simultaneous operation is marked as not allowed the Flash will report an illegal access
only in the cycle the read collision actually happens, maximizing the time the array is available for reading.
Table 21-31. EEPROM Commands
FCMD
Command
Function on EEPROM Memory
0x01
Erase Verify All
Blocks
Verify that all EEPROM (and P-Flash) blocks are erased.
0x02
Erase Verify Block
Verify that the EEPROM block is erased.
0x08
Erase All Blocks
Erase all EEPROM (and P-Flash) blocks.
An erase of all Flash blocks is only possible when the FPLDIS, FPHDIS, and FPOPEN
bits in the FPROT register and the DPOPEN bit in the DFPROT register are set prior to
launching the command.
0x09
Erase Flash Block
Erase a EEPROM (or P-Flash) block.
An erase of the full EEPROM block is only possible when DPOPEN bit in the DFPROT
register is set prior to launching the command.
0x0B
Unsecure Flash
Supports a method of releasing MCU security by erasing all EEPROM (and P-Flash)
blocks and verifying that all EEPROM (and P-Flash) blocks are erased.
0x0D
Set User Margin
Level
Specifies a user margin read level for the EEPROM block.
0x0E
Set Field Margin
Level
Specifies a field margin read level for the EEPROM block (special modes only).
0x10
Erase Verify
EEPROM Section
Verify that a given number of words starting at the address provided are erased.
0x11
Program
EEPROM
Program up to four words in the EEPROM block.
0x12
Erase EEPROM
Sector
Erase all bytes in a sector of the EEPROM block.
0x13
Protection
Override
Supports a mode to temporarily override Protection configuration (for P-Flash and/or
EEPROM) by verifying a key.