NXP Semiconductors MPC5644A, Reference Manual, Page: 225 / 1735

Flash memory
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 225
EER ECC Event Error
EER provides information on previous reads. If a double bit detection occurred, the EER bit is set to a 1.
This bit must then be cleared, or a reset must occur before this bit returns to a 0 state. This bit may not be
set by the user. In the event of a single bit detection and correction, this bit is not be set. If EER is not set,
or remains 0, this indicates that all previous reads (from the last reset, or clearing of EER) are correct.
Since this bit is an error flag, it must be cleared to a 0 by writing a 1 to the register location. A write of 0
has no effect.
0: Reads are occurring normally.
1: An ECC Error occurred during a previous read.
RWE Read While Write Event Error
RWE provides information on previous RWW reads. If a Read While Write error occurs, this bit is set to 1.
This bit must then be cleared, or a reset must occur before this bit returns to a 0 state. This bit may not be
written to a 1 by the user. If RWE is not set, or remains 0, this indicates that all previous RWW reads (from
the last reset, or clearing of RWE) are correct. Since this bit is an error flag, it must be cleared to a 0 by
writing a 1 to the register location. A write of 0 has no effect.
0: Reads are occurring normally.
1: A Read While Write Error occurred during a previous read.
SBC Single Bit Correction
SBC provides information on previous reads provided the UT0[SPCE] is set. If a single bit correction
occurred, the SBC bit is set to a 1. This bit must then be cleared, or a reset must occur before this bit
returns to a 0 state. If SBC is not set, or remains 0, this indicates that all previous reads (from the last
reset, or clearing of SBC) did not require a correction. Since this bit is an error flag, it must be cleared to
a 0 by writing a 1 to the register location. A write of 0 has no effect.
0: Reads are occurring without corrections.
1: A Single Bit Correction occurred during a previous read.
PEAS Program/Erase Access Space
PEAS is used to indicate which space is valid for program and erase operations, either main array space
or shadow space. PEAS = 0 indicates that the main address space is active for all FC program and erase
operations. PEAS = 1 indicates the shadow address space is active for program/erase. The value in
PEAS is captured and held when the shadow block is enabled with the first interlock write done for
program or erase operations. The value of PEAS is retained between sampling events (that is, subsequent
first interlock writes). The value in PEAS may be changed during erase-suspended program, and reverts
back to its’ original state once the erase-suspended program is completed. PEAS is read only.
0: Shadow address space is disabled for program/erase and main address space enabled.
1: Shadow address space is enabled for program/erase and main address space disabled.
DONE State Machine Status
DONE indicates if the flash module is performing a high voltage operation. DONE is set to a 1 on
termination of the flash module reset. DONE is read only. DONE is cleared within a 0 to 1 transition of EHV
which initiates a high voltage operation. DONE is cleared of resuming a suspended operation. DONE is
set to a 1 at the end of program and erase high voltage sequences. DONE is set to a 1 within a 1 to 0
transition of EHV which aborts a high voltage operation.
0: Flash is executing a high voltage operation.
1: Flash is not executing a high voltage operation.
Table 12-4. MCR field description (continued)
Field Description