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Flash memory
MPC5644A Microcontroller Reference Manual, Rev. 6
226
Freescale Semiconductor
PEG
Program/Erase Good
The PEG bit indicates the completion status of the last flash program or erase sequence for which high
voltage operations were initiated. The value of PEG is updated automatically during the program and
erase high voltage operations. Aborting a program/erase high voltage operation causes PEG to be
cleared, indicating the sequence failed. PEG is set to a 1 when the module is reset. PEG is read only.
The value of PEG is valid only when PGM = 1 and/or ERS = 1 and after DONE transitions from 0 to 1 due
to an abort or the completion of a program/erase operation. PEG is valid until PGM/ERS makes a 1 to 0
transition or EHV makes a 0 to 1 transition. The value in PEG is not valid after a 0 to 1 transition of DONE
caused by PSUS or ESUS being set to logic 1. If PGM and ERS are both 1 when DONE makes a qualifying
0 to 1 transition the value of PEG indicates the completion status of the PGM sequence. This happens in
an erase-suspended program operation.
0: Program or erase operation failed
1: Program or erase operation successful
Note:
If program or erases are attempted on blocks that are locked, the response from flash is PEG = 1,
indicating that the operation was successful, and the contents of the block are properly protected
from the program or erase operation.
PGM
Program
PGM is used to set up flash for a program operation. A 0 to 1 transition of PGM initiates a program
sequence. A 1 to 0 transition of PGM ends the program sequence. PGM can be set only under one of the
following conditions:
• User mode read (ERS is low and UTE is low)
• Erase suspend (ERS and ESUS are 1) with EHV low
PGM can be cleared by the user only when PSUS and EHV are low and DONE is high. PGM is cleared
on reset.
0: Flash is not executing a program sequence.
1: Flash is executing a program sequence.
Note:
In an erase-suspended program, programming Flash locations in blocks which were being operated
on in the erase may corrupt FC data. This should be avoided due to reliability implications.
PSUS
Program Suspend
PSUS is used to indicate the flash module is in program suspend or in the process of entering a suspend
state. The module is in program suspend when PSUS = 1 and DONE = 1. PSUS can be set high only
when PGM and EHV are high. A 0 to 1 transition of PSUS starts the sequence which sets DONE and
places the flash module in program suspend. The module enters suspend within this transition.
PSUS can be cleared only when DONE and EHV are high. A 1 to 0 transition of PSUS with EHV = 1 starts
the sequence which clears DONE and returns the flash module to program. The module cannot exit
program suspend and clear DONE while EHV is low. PSUS is cleared on reset.
0: Program sequence is not suspended.
1: Program sequence is suspended.
ERS
Erase
ERS is used to set up flash for an erase operation. A 0 to 1 transition of ERS initiates an erase sequence.
A 1 to 0 transition of ERS ends the erase sequence. ERS can only be set only in user mode read (PGM
is low and UTE is low). ERS can be cleared by the user only when ESUS and EHV are low and DONE is
high. ERS is cleared on reset.
0: Flash is not executing an erase sequence.
1: Flash is executing an erase sequence.
Table 12-4. MCR field description (continued)
Field
Description
Summary of Contents for MPC5644A
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Page 52: ...Introduction MPC5644A Microcontroller Reference Manual Rev 6 52 Freescale Semiconductor...
Page 56: ...Memory Map MPC5644A Microcontroller Reference Manual Rev 6 56 Freescale Semiconductor...
Page 1228: ...Decimation Filter MPC5644A Microcontroller Reference Manual Rev 6 1228 Freescale Semiconductor...
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