MOTOROLA
Chapter 21. CDR3 Flash (UC3F) EEPROM
21-13
Programming Model
2
PEFI
Program/erase fail indicator. The PEFI bit is a status qualifier for the PEGOOD bit and is valid for
the same times that PEGOOD is valid. In the event of an erase failure which returns PEGOOD
= 0, the PEFI bit provides diagnostic information for the cause of the erase failure.
If PEFI = 0, the erase failure occurred during the preprogramming step of the erase operation. If
PEFI = 1, the erase failure occurred during the actual erase or APDE steps of the erase
operation.
In the event of a program failure which returns PEGOOD = 0, the PEFI bit indicates a program
failure by reading as a 0. The PEFI bit should never return a 1 for a program failure.
NOTE: The PEFI bit is meaningful only while PEGOOD is valid and PEGOOD = 0. PEFI is valid
after HVS negates and prior to the assertion of EHV or negation of SES.
0 Program operation failed if PEGOOD = 0
1 Erase operation failed if PEGOOD = 0
3
EPEE
EPEE pin status. The EPEE bit monitors the state of the external program/erase enable (EPEE)
input. The UC3F module samples the EPEE input when EHV is asserted and holds that sampled
state until EHV is negated.
0 high voltage operations are not possible
1 high voltage operations are possible
4
B0EM
Block 0 EPEE pin status. The B0EM bit monitors the state of the Block 0 EPEE, B0EPEE, input.
The UC3F module samples the B0EPEE input when EHV is asserted and holds that sampled
value until EHV is negated.
If B0EM = 1 when EHV is asserted, high voltage operations such as program or erase are
enabled for either small block 0 or the lowest numbered block of the UC3F array regardless of
the state of EPEE.
If B0EM = 0 when EHV is asserted, high voltage operations are disabled for small block 0 or the
lowest numbered block of the UC3F array regardless of the state of EPEE.
0 High voltage operations are not possible for block 0 or lowest numbered block
1 High voltage operations are possible for block 0 or lowest numbered block.
5:13
—
Reserved
14:15
SBBLOCK Small block program and erase select. The SBBLOCK bits are write-protected by the SES bit.
SBBLOCK selects the UC3F EEPROM small array blocks for program and erase operation.
When programming, only those blocks intended to be enabled for programming should have
their corresponding BLOCK[M] or SBBLOCK[M] bit set.
0 Small block M is not selected for program or erase
1 Small Block M is selected for program or erase
Table 21-5. UC3FCTL Bit Descriptions (continued)
Bits
Name
Description