Double DATA RATE 2 SDRAM AC Timing

Double DATA RATE 2 SDRAM AC Timing
Contents
1. Bank Activate Command
2. Read Burst Timing
3. Read followed by a write to the same bank I
4. Read followed by a write to the same bank II
5. Read followed by a write to the same bank III
6. Basic Burst Read Timing
7. Burst Read Operation
8. Burst Read Operation
9. Burst Read followed by BurstWrite
10. Seamless Burst Read Operation I
11. Seamless Burst Read Operation II
12. Basic Burst Write Timing
13. Burst Write Operation I
14. Burst Write Operation II
15. Burst Write followed by Burst Read
16. Seamless Burst Write Operation I
17. Seamless Burst Write Operation II
18. Write Data Mask Timing
19. Burst Write Operation with Data Mask
20. Read Burst Interrupt Timing
21. Write Burst Interrupt Timing
22. Burst Read Followed by Precharge I
Nov. 2010
23. Burst Read Followed by Precharge II
24. Burst Read Followed by Precharge III
25. Burst Read Followed by Precharge IV
26. Burst Read Followed by Precharge V
27. Burst Write followed by Precharge I
28. Burst Write followed by Precharge II
29. Burst Read with Auto-Precharge I
30. Burst Read with Auto-Precharge II
31. Burst Read with Auto-Precharge III
32. Burst Read with Auto-Precharge IV
33. Burst Write with Auto-Precharge I
34. Burst Write with Auto-Precharge II
35. Auto-Refresh Command
36. Self-Refresh Command
37. Active Power-Down Mode Entry I
38. Active Power-Down Mode Entry II
39. Active Power-Down Mode Entry III
40. Precharge Power Down Mode Entry and Exit
1/40
www.eorex.com
1. Bank Activate Command: tRCD=3, AL=2, tRP=3, tRRD=2
Nov. 2010
2/40
www.eorex.com
2. Read Burst Timing: CL=3, AL=0, RL=3, BL=4
Nov. 2010
3/40
www.eorex.com
3. Read followed by a write to the same bank I: Activate to Read delay < tRCDmin
AL = 2 and CL = 3, RL = (AL + CL) = 5, WL = (RL -1) = 4, BL = 4
4. Read followed by a write to the same bank II: Activate to Read delay < tRCDmin
AL = 2 and CL = 3, RL = (AL + CL) = 5, WL = (RL -1) = 4, BL = 8
Nov. 2010
4/40
www.eorex.com
5. Read followed by a write to the same bank III: Activate to Read delay < tRCDmin
AL = 1, CL = 3, RL = 4, WL = 3, BL = 4
Nov. 2010
5/40
www.eorex.com
6. Basic Burst Read Timing
Nov. 2010
6/40
www.eorex.com
7. Burst Read Operation: RL = 5 (AL = 2, CL = 3, BL = 4)
Nov. 2010
7/40
www.eorex.com
8. Burst Read Operation: RL = 3 (AL = 0, CL = 3, BL = 8)
Nov. 2010
8/40
www.eorex.com
9. Burst Read followed by BurstWrite : RL = 5, WL = (RL-1) = 4, BL = 4
The minimum time from the burst read command to the burst write command is defined by a read-to-write turn-around time, which is BL/2 + 2 clocks.
Nov. 2010
9/40
www.eorex.com
10. Seamless Burst Read Operation I: RL = 5, AL = 2, CL = 3, BL = 4
Nov. 2010
10/40
www.eorex.com
11. Seamless Burst Read Operation II: RL = 3, AL = 0, CL = 3, BL = 8 (non interrupting)
Nov. 2010
11/40
www.eorex.com
12. Basic Burst Write Timing
Nov. 2010
12/40
www.eorex.com
13. Burst Write Operation I: RL = 5 (AL = 2, CL = 3), WL = 4, BL = 4
Nov. 2010
13/40
www.eorex.com
14. Burst Write Operation II: RL = 3 (AL = 0, CL = 3), WL = 2, BL = 4
Nov. 2010
14/40
www.eorex.com
15. Burst Write followed by Burst Read: RL = 5 (AL = 2, CL = 3), WL = 4, tWTR = 2, BL = 4
The minimum number of clocks from the burst write command to the burst read command is (CL - 1) +BL/2 + tWTR where tWTR is the write-to-read
turn-around time tWTR expressed in clock cycles. The tWTR is not a write recovery time (tWR) but the time required to transfer 4 bit write data from the
input buffer into sense amplifiers in the array.
Nov. 2010
15/40
www.eorex.com
16. Seamless Burst Write Operation I: RL=5, WL=4, BL=4
Nov. 2010
16/40
www.eorex.com
17. Seamless Burst Write Operation II: RL=3, WL=2, BL=8, non-interrupting
Nov. 2010
17/40
www.eorex.com
18. Write Data Mask Timing
Nov. 2010
18/40
www.eorex.com
19. Burst Write Operation with Data Mask: RL = 3 (AL = 0, CL = 3), WL = 2, tWR = 3, BL = 4
Nov. 2010
19/40
www.eorex.com
20. Read Burst Interrupt Timing: (CL = 3, AL = 0, RL = 3, BL = 8)
Nov. 2010
20/40
www.eorex.com
21. Write Burst Interrupt Timing: (C L = 3, AL = 0, WL = 2, BL = 8)
Nov. 2010
21/40
www.eorex.com
22. Burst Read Followed by Precharge I: RL = 4 (AL = 1, CL = 3), BL = 4, tRTP <= 2 clocks
Nov. 2010
22/40
www.eorex.com
23. Burst Read Followed by Precharge II: RL = 4 (AL = 1, CL = 3), BL = 8, tRTP <= 2 clocks
Nov. 2010
23/40
www.eorex.com
24. Burst Read Followed by Precharge III: RL=5(AL=2, CL=3), BL=4, tRTP<=2 clocks
Nov. 2010
24/40
www.eorex.com
25. Burst Read Followed by Precharge IV: RL=6(AL=2, CL=4), BL=4, tRTP<=2 clocks
Nov. 2010
25/40
www.eorex.com
26. Burst Read Followed by Precharge V: RL=4, (AL=0, CL=4), BL=8, tRTP>2 clocks
Nov. 2010
26/40
www.eorex.com
27. Burst Write followed by Precharge I: WL = (RL - 1) = 3, BL = 4, tWR = 3
Nov. 2010
27/40
www.eorex.com
28. Burst Write followed by Precharge II: WL = (R L - 1) = 4, BL = 4, tWR = 3
Nov. 2010
28/40
www.eorex.com
29. Burst Read with Auto-Precharge I: followed by an activation to the Same Bank (tRC Limit)
RL = 5 (AL = 2, CL = 3), BL = 4, tRTP <= 2 clocks
Nov. 2010
29/40
www.eorex.com
30. Burst Read with Auto-Precharge II: followed by an Activation to the Same Bank (tRAS Limit)
RL = 5 (AL = 2, CL = 3), BL = 4, tRTP <= 2 clocks
Nov. 2010
30/40
www.eorex.com
31. Burst Read with Auto-Precharge III: followed by an Activation to the Same Bank
RL=4(AL=1, CL=3), BL=8, tRTP<=2 clocks
Nov. 2010
31/40
www.eorex.com
32. Burst Read with Auto-Precharge IV: followed by an Activation to the Same Bank
RL=4(AL=1, CL=3), BL=4, tRTP>2 clocks
Nov. 2010
32/40
www.eorex.com
33. Burst Write with Auto-Precharge I: WL = 2, tDAL = 6 (WR = 3, tRP = 3), BL = 4 tRC Limit)
Nov. 2010
33/40
www.eorex.com
34. Burst Write with Auto-Precharge II: WL=4, tDAL=6(WR=3, tRP=3), BL=4 (WR+tRP Limit)
Nov. 2010
34/40
www.eorex.com
35. Auto-Refresh Command
Nov. 2010
35/40
www.eorex.com
36. Self-Refresh Command
Nov. 2010
36/40
www.eorex.com
37. Active Power-Down Mode Entry I: and Exit after an Activate Command
Nov. 2010
37/40
www.eorex.com
38. Active Power-Down Mode Entry II: and Exit after a Read Burs t: R L = 4 (AL = 1, CL =3), BL = 4
Nov. 2010
38/40
www.eorex.com
39. Active Power-Down Mode Entry III: and Exit after a Write Burst: WL = 2, tWTR = 2, BL = 4
Nov. 2010
39/40
www.eorex.com
40. Precharge Power Down Mode Entry and Exit
Nov. 2010
40/40
www.eorex.com