Write down your project requirements

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David Prentice
05/24/12 04:54
Read: 387 times
Wormshill
England

#187491 - Write down your project requirements
Responding to: ???'s previous message

Specify the number of external port lines that you need.
Sometimes pins can be shared.

Calculate the RAM / EEPROM that may be needed.

A single chip solution can often avoid any external memory bus.
Your physical chip size then depends on your GPIO requirements.

You seldom need super fast access to all RAM or EEPROM, so it is also worth considering external SPI or I2C chips if you can't find quite enough memory in a single microcontroller.

Your options are very wide. Getting your design requirements down on paper will speed you through.

David.

List of 29 messages in thread

Topic Author Date
More Ports or Non-Volatile RAM       Kurt Adam       05/23/12 17:47
   Numbers always help       Jim Granville       05/23/12 22:17
   Trying to read your mind       Michael Karas       05/23/12 22:48
   Write down your project requirements       David Prentice       05/24/12 04:54
      Details       Kurt Adam       05/24/12 05:48
         Most projects do not need external memory       David Prentice       05/24/12 06:20
            SILabs have 8-porters         Erik Malund       05/24/12 07:30
               Don't overlook the additional memory ...       Richard Erlacher       05/24/12 09:09
            Further Details and Thankyou       Kurt Adam       05/24/12 08:44
               AT89S8253 ?       Jim Granville       05/24/12 16:04
                  This worked. Thanks       Kurt Adam       05/30/12 17:54
                     Hold your horses       Hans Van Pelt       05/31/12 03:04
                        F-RAM       Per Westermark       05/31/12 05:31
                           Yes! I like 'em, and there's no write delay       Richard Erlacher       05/31/12 06:38
                        3 things       Erik Malund       05/31/12 07:33
         some or all?       Erik Malund       05/24/12 09:42
            Re:some or all       Kurt Adam       05/24/12 09:50
               how much and can you       Erik Malund       05/24/12 10:07
               Options       David Good       05/24/12 10:08
   Had you read the datasheets ...       Richard Erlacher       05/24/12 09:06
      sorry       Kurt Adam       05/24/12 09:22
         I doubt it'll hurt you ...       Richard Erlacher       05/25/12 08:16
            WOW       Erik Malund       05/25/12 09:48
               Yes       Per Westermark       05/26/12 03:32
               Well, it is a troll, as someone has pointed out ...       Richard Erlacher       05/26/12 07:04
                  "his" money       Erik Malund       05/26/12 07:54
                     You're probably right. It's a shame, but it's so       Richard Erlacher       05/26/12 19:31
            Is that true?       Andy Neil       06/05/12 05:19
               I doubt it ...       Richard Erlacher       06/05/12 09:55

Back to Subject List

Topic	Author	Date
More Ports or Non-Volatile RAM	Kurt Adam	05/23/12 17:47
Numbers always help	Jim Granville	05/23/12 22:17
Trying to read your mind	Michael Karas	05/23/12 22:48
*Write down your project requirements*	David Prentice	05/24/12 04:54
Details	Kurt Adam	05/24/12 05:48
Most projects do not need external memory	David Prentice	05/24/12 06:20
SILabs have 8-porters	Erik Malund	05/24/12 07:30
Don't overlook the additional memory ...	Richard Erlacher	05/24/12 09:09
Further Details and Thankyou	Kurt Adam	05/24/12 08:44
AT89S8253 ?	Jim Granville	05/24/12 16:04
This worked. Thanks	Kurt Adam	05/30/12 17:54
Hold your horses	Hans Van Pelt	05/31/12 03:04
F-RAM	Per Westermark	05/31/12 05:31
Yes! I like 'em, and there's no write delay	Richard Erlacher	05/31/12 06:38
3 things	Erik Malund	05/31/12 07:33
some or all?	Erik Malund	05/24/12 09:42
Re:some or all	Kurt Adam	05/24/12 09:50
how much and can you	Erik Malund	05/24/12 10:07
Options	David Good	05/24/12 10:08
Had you read the datasheets ...	Richard Erlacher	05/24/12 09:06
sorry	Kurt Adam	05/24/12 09:22
I doubt it'll hurt you ...	Richard Erlacher	05/25/12 08:16
WOW	Erik Malund	05/25/12 09:48
Yes	Per Westermark	05/26/12 03:32
Well, it is a troll, as someone has pointed out ...	Richard Erlacher	05/26/12 07:04
"his" money	Erik Malund	05/26/12 07:54
You're probably right. It's a shame, but it's so	Richard Erlacher	05/26/12 19:31
Is that true?	Andy Neil	06/05/12 05:19
I doubt it ...	Richard Erlacher	06/05/12 09:55