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