Boot Block of NOR flash memories ??

HI,
   I have the following queries based on the Flash Memory,

000. What is the advantage of Top Boot Flash Memory and
        What is the advantage of Bottom Boot Flash memory ?

001. what are the other differences between these Boot Block based
Flash memories
and Normal Flash Memories ?


Satish

HI,
   I have the following queries based on the Flash Memory,

000. What is the advantage of Top Boot Flash Memory and
        What is the advantage of Bottom Boot Flash memory ?

001. what are the other differences between these Boot Block based
Flash memories
and Normal Flash Memories ?


Satish

On 14.4.10 8:40 , satish.aradhya wrote:
> HI,
>     I have the following queries based on the Flash Memory,
>
> 000. What is the advantage of Top Boot Flash Memory and
>          What is the advantage of Bottom Boot Flash memory ?
>
> 001. what are the other differences between these Boot Block based
> Flash memories
> and Normal Flash Memories ?
>
>
> Satish

This has a strong smell of a study assignment, but ...

001. Boot block is an erase block which is split into
      smaller pieces than an usual erase block on the chip.

000. A bottom boot chip has split the lowest-address
      erase block into smaller pieces, a top-boot chip
      has the split block at the highest addresses of the chip.

-- 

Tauno Voipio, MSEE
tauno voipio (at) iki fi

satish.aradhya wrote:
> HI,
>    I have the following queries based on the Flash Memory,
> 
> 000. What is the advantage of Top Boot Flash Memory and
>         What is the advantage of Bottom Boot Flash memory ?
> 
> 001. what are the other differences between these Boot Block based
> Flash memories
> and Normal Flash Memories ?

Professor says do your own homework.

Hint, where does a 68000 start executing code on
startup?  An x86 processor?

On Apr 13, 10:21=A0pm, whygee <y...@yg.yg> wrote:
> satish.aradhya wrote:
> > HI,
> > =A0 =A0I have the following queries based on the Flash Memory,
>
> > 000. What is the advantage of Top Boot Flash Memory and
> > =A0 =A0 =A0 =A0 What is the advantage of Bottom Boot Flash memory ?
>
> the Top Boot is faster.
> The bits fall from higher.
>

Wrong, wrong, wrong.  (Not true.)  The bits from the top-boot have to
filter down through all of the non-boot blocks, which takes -longer-.

Especially if the non-boot blocks are programmed - 1 bits have a lower
co-efficient of friction than 0 bits do.

The real problem with bottom-boot is that if you do a lot of
debugging, all the dead bugs tend to collect there and clutter things
up.

RK.

d_s_klein wrote:
> On Apr 13, 10:21 pm, whygee <y...@yg.yg> wrote:
>> satish.aradhya wrote:
>>> HI,
>>>    I have the following queries based on the Flash Memory,
>>> 000. What is the advantage of Top Boot Flash Memory and
>>>         What is the advantage of Bottom Boot Flash memory ?
>> the Top Boot is faster.
>> The bits fall from higher.
> 
> Wrong, wrong, wrong.  (Not true.)  The bits from the top-boot have to
> filter down through all of the non-boot blocks, which takes -longer-.
> 
> Especially if the non-boot blocks are programmed - 1 bits have a lower
> co-efficient of friction than 0 bits do.
> 
> The real problem with bottom-boot is that if you do a lot of
> debugging, all the dead bugs tend to collect there and clutter things
> up.

damn right. I completely forgot those implementation details.
That's why I prefer to use magnetic bubble memory.

> RK.
yg

-- 
http://ygdes.com / http://yasep.org

Jim Stewart wrote:
>> Wrong, wrong, wrong.  (Not true.)  The bits from the top-boot have to
>> filter down through all of the non-boot blocks, which takes -longer-.
> That's why I always invert the address bits.
oh, yes, just flip the MSB.
the price of a single-gate inverter like SN74LVC1G04 is not so high today.
But isn't the inverter gate's delay over-compensating the faster access ?

yg
-- 
http://ygdes.com / http://yasep.org

d_s_klein wrote:
> On Apr 13, 10:21 pm, whygee <y...@yg.yg> wrote:
>> satish.aradhya wrote:
>>> HI,
>>>    I have the following queries based on the Flash Memory,
>>> 000. What is the advantage of Top Boot Flash Memory and
>>>         What is the advantage of Bottom Boot Flash memory ?
>> the Top Boot is faster.
>> The bits fall from higher.
>>
> 
> Wrong, wrong, wrong.  (Not true.)  The bits from the top-boot have to
> filter down through all of the non-boot blocks, which takes -longer-.

That's why I always invert the address bits.

> Especially if the non-boot blocks are programmed - 1 bits have a lower
> co-efficient of friction than 0 bits do.
> 
> The real problem with bottom-boot is that if you do a lot of
> debugging, all the dead bugs tend to collect there and clutter things
> up.
> 
> RK.

Jim Stewart wrote:
> whygee wrote:
>> But isn't the inverter gate's delay over-compensating the faster access ?
> Not if you get the inversion by soldering the memory chip upside-down.
but then you will get all your data negated !
so this displaces the inverter gates from
the address bus to the data bus, with no speed gain.

yg
-- 
http://ygdes.com / http://yasep.org

whygee wrote:
> Jim Stewart wrote:
>>> Wrong, wrong, wrong.  (Not true.)  The bits from the top-boot have to
>>> filter down through all of the non-boot blocks, which takes -longer-.
>> That's why I always invert the address bits.
> oh, yes, just flip the MSB.
> the price of a single-gate inverter like SN74LVC1G04 is not so high today.
> But isn't the inverter gate's delay over-compensating the faster access ?

Not if you get the inversion by soldering the memory
chip upside-down.