
PSD4000 Series
Preliminary Information
22
9.1.1.6.2 Data Toggle
(cont.)
It is suggested (as with all Flash memories) to read the location again after the embedded
programming algorithm has completed to compare the word that was written to Flash with
the word that was intended to be written.
When using the Data Toggle method after an erase instructin, Figure 4 still applies. DQ6
(DQ14) will toggle until the erase operation is complete. A
‘
1
’
on DQ5 (DQ13) will indicate
a timeout failure of the erase operation, a
‘
0
’
indicates no error. The MCU can read any
even location within the sector being erased to get DQ6 (DQ14) and DQ5 (DQ13) .
PSDsoft generates ANSI C code functions which implement these Data Toggling
algorithms.
The
PSD4000
Functional
Blocks
(cont.)
Figure 4. Data Toggle Flow Chart
START
READ DQ5 & DQ6
(DQ13 & DQ14)
at VALID EVEN ADDRESS
NO
YES
NO
YES
YES
NO
DQ6
(D=
TOGGLE
DQ5
(DQ13)
=1
READ DQ6
(DQ14)
FAIL
Program/Erase
Operation Failed
Issue Reset Instruction
PASS
Program/Erase
Operation is
Completed
DQ6
(D=
TOGGLE