Texas Instruments TMS320F20x/F24x DSP manual Flash-Write Algorithm, Preliminary

Flash-Write Algorithm

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

Clear algorithm

Erase algorithm

Start

X = 1

Clear the

array

Erase the

array

Bits in

depletion?

No

Initialization flow

	Flash-write
		Recover using
	algorithm
		flash-write
		X = X+1
Yes			Yes
		X < 10 ?

No

Fail

Yes

No

Reprogram?

Done/Stop

Program the array

Programming algorithm

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.

3-14 PRELIMINARY