Why label as DVDD_1V8 as DVDDR2?

Anonymous

Hi All,

I would like to ask one question on DM6437 voltage pin.

In page 17 of SPRS345d, pin P7 is labeled as DV_DDR2, while in the actual PCB layout (magnified view of EVM6437 PCB layout) it is denoted as DV_{DD_1V8}.

So it seems that R2 is a short representation for 1V8 (1.8V)? Why this shortcut (R2) is chosen? Does R stand for “around” or “round”?

Thanks,

Zheng

over 14 years ago

0 Muhammad Haque over 14 years ago

TI__Intellectual 1000 points

R2 is not short for 1.8V.

DDR2 IO supply is 1.8V. To distinguish these supply pins from other 1.8V supply pins or to be more specific in other word, these pins are labeled DVddr2 in the data sheet.

0 Anonymous over 14 years ago in reply to Muhammad Haque

Dear Muhammad,

So is there any inherent reason why "R2" is chosen for distinguishing, or it was just arbitrarily picked and in this sense it has no difference from "A1", "X3" alike?

Zheng

0 Muhammad Haque over 14 years ago in reply to Anonymous

TI__Intellectual 1000 points

Actually the qualifier is DDR2 (as DV pin for DDR2 IO buffer). It appears you are interpreting it incorrectly as DVDD + R2.

0 Anonymous over 14 years ago in reply to Anonymous

I need to check it again. Please allow me some time.

Zheng

0 Anonymous over 14 years ago in reply to Muhammad Haque

I got it in table 5-2:

Zheng

Processors

Processors forum

Why label as DVDD_1V8 as DVDDR2?