Table of Contents
Advertisement
UC3F Operation
The array blocks selected for erase operation are determined by BLOCK[0:7],
SBBLOCK[0:1] in conjunction with SBEN[0:1], and the array configuration. If multiple
blocks are selected for erase, the embedded erase hardware algorithm serially erases each
array block until all of the selected blocks are erased. For instance, if BLOCK[0:7] = 0x78
and SBEN[0:1] = 0b00, then blocks 1, 2, 3, and 4 are selected for erase. The embedded
erase hardware algorithm first erases block 1 and then erases block 2 followed by blocks 3
and 4. The total erase time for this example is the block erase time, T
four since four blocks are erased. In addition, the preprogramming time to program all
locations in blocks 1, 2, 3, and 4 to a "0" state needs to be considered when determining the
total erase time. The preprogramming time is dependent on the data already stored in the
Flash array before beginning the erase operation.
19.3.8.1 Erase Sequence
The UC3F EEPROM module requires a sequence of writes to the high voltage control
register (UC3FCTL) and an erase interlock write in order to enable high voltage to the array
and shadow information for erase operation. The required hardware algorithm erase
sequence follows.
1. Write PROTECT[0:7] and SBPROTECT[0:1] to disable protect for the blocks to be
erased.
2. Write BLOCK[0:7] and SBBLOCK[0:1] to select the blocks to be erased, PE = 1
and SES = 1 in the UC3FCTL register.
BLOCK[0:7] and SBBLOCK[0:1] in conjunction with
SBEN[0:1] determine which blocks are selected for erase.
Blocks whose BLOCK bits or enabled small blocks whose
SBBLOCK bits are set (equal to 1) get erased when an erase
operation is performed.
3. Execute an erase interlock write to any UC3F array location.
4. Write EHV = 1 in the UC3FCTL register.
The values of the EPEE and B0EPEE inputs are latched with
the assertion of EHV to determine the array protection state for
the erase operation. It is assumed that the EPEE and B0EPEE
inputs are setup prior to the assertion of EHV.
5. Read the UC3FCTL register until HVS = 0.
19-26
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
NOTE
NOTE
MPC533 Reference Manual
, multiplied by
ERASE
MOTOROLA
Advertisement
Table of Contents
