Hi, 

> I want to ask that how many times an MSP430 Flash
can be programmed 
> and erased? 

100.000 times. This is the usual limit for Flash. 


> For how long the data in the flash remain there? 

Minimum 30 years. 

Another question: How much time does Flash reading and writing need? I could
find the answer neither in the users's guide nor an application note. 

Regards 

Rolf F.

nobodyo@nobo... wrote:

> Hi, 
> 
> 
>>I want to ask that how many times an MSP430 Flash can be programmed 
>>and erased? 
> 
> 
> 100.000 times. This is the usual limit for Flash. 
> 
> 
> 
>>For how long the data in the flash remain there? 
> 
> 
> Minimum 30 years. 
> 
> Another question: How much time does Flash reading and writing need? I
could find the answer neither in the users's guide nor an application note.

> 
> Regards 
> 
> Rolf F.

tHIS IS DEFINITELY NOT MADE CLEAr. You do get to know the FTG frequency, 
and that the cumulative segment program time is 3ms, so you know that 
programming takes no more than this ona  byte/word basis. And that a 
segment should program within this time. You actually have to go to 
SLAU049 and study the timing drawings to figure outactual flash timing. 
In SLAU049C page 5-5 tells you that a segment erase takes 4891/F(ftg), 
while a mass erase takes 5297/F(ftg). On page 5-8 you find that a word 
write takes 33/F(ftg) (and I presume a byte takes the same). Block 
writes are a little more complex, see the diagram on page 5-11.

 From this a segment erase takes 10.2 and 19msecs. A mass erase takes 
from 11.1 to 20.6msecs and a word or byte write takes between 69.3 and 
128.4 microseconds. This assumes that the Flash clock is within the 
specified limits of 257kHz to 476kHz, and does not take into accoun the 
few microseconds of programming time required to manage the flash 
erase/write cycles.

Al

> Another question: How much time does Flash reading and 
> writing need? I could find the answer neither in
the users's 
> guide nor an application note. 

You can read the number of cycles required for word mode and block mode
flashing; 30 cycles for a word mode program at f(FTG), where f(FTG) is
between approx 200KHz and 470KHz.  Timing and details are in the data
sheets.

--
Paul Curtis, Rowley Associates Ltd http://www.rowley.co.uk
CrossWorks for MSP430 and ARM processors