Texas Instruments TMS320F20x/F24x DSP Computer Drive User Manual


 
Flash-Write Algorithm
PRELIMINARY
3-14
PRELIMINARY
3.4 Flash-Write Algorithm
The flash-write operation recovers bits in depletion mode, which can be
caused by over-erasure. The flash-write algorithm’s place in the overall flow
is highlighted in Figure 3–6.
Figure 3–6. Flash-Write Algorithm in the Overall Flow
Flash-write
algorithm
Erase
algorithm
Clear
algorithm
X = X+1
flash-write
Recover using
Fail
Yes
No
X < 10 ?
array
Erase the
Clear the
array
No
Yes
Reprogram?
Bits in
depletion?
X = 1
Start
Program
the array
Initialization flow
Programming
algorithm
No
Yes
Done/Stop
A
flash-write pulse
is the time during the flash-write operation between the set-
ting and the clearing of the EXE bit (bit 0 of SEG_CTR). Charge is added to
the bits of the flash memory array via the flash-write mechanism. The flash-
write algorithm may require multiple flash-write pulses. The steps required to
apply one flash-write pulse are outlined in Table 3–3.