May 28, 2004 #1 I Ivanw Newbie level 4 Joined Apr 23, 2004 Messages 7 Helped 0 Reputation 0 Reaction score 0 Trophy points 1,281 Activity points 53 data mask ram :?: I saw a RAM chip define two pins as Data Mask , and they are LDQM & UDQM . What is "Data Mask" ? Mask the output data ?
data mask ram :?: I saw a RAM chip define two pins as Data Mask , and they are LDQM & UDQM . What is "Data Mask" ? Mask the output data ?
May 29, 2004 #2 C clivechen Member level 3 Joined May 29, 2004 Messages 65 Helped 1 Reputation 2 Reaction score 1 Trophy points 1,288 Activity points 500 mask of ram i think the mask is that you must distinguish the rams with others. so you need a mask! you can see the website https://www.esrf.fr/computing/scientific/FIT2D/FIT2D_REF/node205.html
mask of ram i think the mask is that you must distinguish the rams with others. so you need a mask! you can see the website https://www.esrf.fr/computing/scientific/FIT2D/FIT2D_REF/node205.html
May 29, 2004 #3 V vomit Full Member level 2 Joined Jun 14, 2002 Messages 148 Helped 14 Reputation 28 Reaction score 4 Trophy points 1,298 Activity points 1,527 Ivanw said: :?: I saw a RAM chip define two pins as Data Mask , and they are LDQM & UDQM . What is "Data Mask" ? Mask the output data ? Click to expand... The RAM chip is apparently 16-bits wide. So each write affects 16 bit. If you only want to write the lower or upper byte and keep the other byte untouched, you must mask off the other byte using the Upper DQ Mask or Lower DQ Mask, respectively. For 32-bit chips you'll find 4 mask pins, etc.
Ivanw said: :?: I saw a RAM chip define two pins as Data Mask , and they are LDQM & UDQM . What is "Data Mask" ? Mask the output data ? Click to expand... The RAM chip is apparently 16-bits wide. So each write affects 16 bit. If you only want to write the lower or upper byte and keep the other byte untouched, you must mask off the other byte using the Upper DQ Mask or Lower DQ Mask, respectively. For 32-bit chips you'll find 4 mask pins, etc.