Win a copy of Think Java: How to Think Like a Computer Scientist this week in the Java in General forum!
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic

About Memeory Budget

 
Song Lixin
Greenhorn
Posts: 19
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hello,
In CLDC 1.1:
The CLDC Specification assumes that:
■ At least 160 kilobytes of non-volatile1 memory
machine and CLDC libraries.
■ At least 32 kilobytes of volatile memory2
runtime (for example, the object heap.)

In MIDP 2.0:
256 kilobytes of non-volatile memory for the MIDP implementation, beyond what's required for CLDC.
8 kilobytes of non-volatile memory for application-created persistent data
128 kilobytes of volatile memory for the Java runtime (e.g., the Java heap)


Does this means that for a MID that implements cldc1.1+midp2.0 will at least have:

160k+256K non-volatile memory and
8 + 128 k volatile memory

right?
 
Theodore Casser
Ranch Hand
Posts: 1902
Hibernate Netbeans IDE PHP
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
No. MIDP 2.0 and CLDC 1.0/1.1 are complimentary, not additive, requirements. MIDP 2.0 requires CLDC 1.0 or 1.1, and so the MIDP 2.0 requirements are in lieu of those required for the CLDC.
 
Eduardo Marques
Ranch Hand
Posts: 231
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
"non-volatile memory for application-created persistent data"
refers to RMS storage size.
 
Song Lixin
Greenhorn
Posts: 19
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
So:
Min non-volatile memory : 160k fou CLDC, 256k for MIDP, 8k for RMS
Min volatile memory: 128 k volatile memory

I still has not read JTWI so it's only mean for CLDC + MIDP.
 
Theodore Casser
Ranch Hand
Posts: 1902
Hibernate Netbeans IDE PHP
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Originally posted by Song Lixin:
So:
Min non-volatile memory : 160k fou CLDC, 256k for MIDP, 8k for RMS
Min volatile memory: 128 k volatile memory

I still has not read JTWI so it's only mean for CLDC + MIDP.


JTWI is just a specification to "standardize" how CLDC and MIDP and other Java ME technologies are implemented in the mobile industry. (Basically, in other words, any JTWI-compliant device should have at least 256k of non-volatile memory and 128k of volatile, etc., since MIDP enhances CLDC's requirements...)
 
Ko Ko Naing
Ranch Hand
Posts: 3178
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Song,
The memory information are just for the implementers to follow while they are implementating a device. In the other words, those limits must be satisfied when someone claims that their implementation is CLDC1.1- or MIDP2.0-compliant.

But they are a must for an exam taker to know.
 
Song Lixin
Greenhorn
Posts: 19
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Thx a lot! All!
I have read all the spec and APIs and also Sathy's notes.

I will take the exam soon.
 
  • Post Reply
  • Bookmark Topic Watch Topic
  • New Topic