DRAM in Personal Computes Richard L. Goldman ©February 1, 2001

Evolution of Popular Types of PC DRAM DRAM – Dynamic RAM FPM DRAM – Fast Page Mode Dynamic RAM Paging Bursting Interleaving EDO DRAM – Extended Data Out Dynamic RAM BEDO DRAM – Burst EDO Dynamic RAM SD RAM – Synchronous Dynamic RAM DRD RAM – Direct Rambus Dynamic RAM DDR RAM – Double Data Rate RAM

5-5-5-5 1 2 3 4 5 6 7 8 9 Standard DRAM 1. Select Row 2. Select Column A B C D E F G H I J K L M N 1 2 3 4 5 6 7 8 9 1. Select Row 2. Select Column 3. Transfer Data

5-3-3-3 1 2 3 4 5 6 7 8 9 FPM DRAM Paging 1. Select Row A B C D E F G H I J K L M N 1 2 3 4 5 6 7 8 9 1. Select Row 2. Select Column 3. Transfer Data

1 2 3 4 5 6 7 8 9 FPM DRAM Bursting 1. Select Row 2. Select Column A B C D E F G H I J K L M N 1 2 3 4 5 6 7 8 9 1. Select Row 3. Transfer Data

FPM DRAM Interleaving A B C D E F G H I J K L M N A B C D E F G H I J K L M N 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1. Select Row 1. Select Row 2. Select Column 2. Select Column 3. Transfer Data 3. Transfer Data

5-2-2-2 1 2 3 4 5 6 7 8 9 EDO DRAM 1. Select Row 2. Select Column A B C D E F G H I J K L M N 1 2 3 4 5 6 7 8 9 1. Select Row 3. Transfer Data

5-5-5-5 1 2 3 4 5 6 7 8 9 BEDO DRAM 1. Select Row 2. Select Column A B C D E F G H I J K L M N 1 2 3 4 5 6 7 8 9 1. Select Row 3. Transfer Data