Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Altera_Forum
Honored Contributor I
776 Views

DDR3 RESET implementation overview

Dear Gurus, 

 

We are recently having invalid data when we reset our DDR3. Below there is Altera Documentation and my questions. 

We are using Quartus 11.1, with StratixIII-EP3SL70-F780C4 

 

 

DDR3 SDRAM Controller with UniPHY Interfaces 

 

 

global_reset_n 

reset input 

Asychronous global reset for PLLand all logic in PHY 

 

 

soft_reset_n 

reset input 

Asychronous reset input. Resets thePHY, but not the PLL that the PHYuses. 

 

 

afi_reset_n 

reset output(PLL master) 

Reset output ofthe AFI interface. This interface isasserted when the PLL loses lock orthe PHY is reset. 

 

 

 

 

 

Questions: 

1- Should we connect the power up reset input(Input of FPGA coming from PCB) to global reset_n? 

2- should we use afi_reset_n output at all? 

3- Should we connect the afi_reset_n output of the fpga to global reset_n not to soft reset_n because we want to reset the pll it is out of lock? 

4- when should we use soft_reset_n, what is the advantage of using soft_reset_n, does it allow to recalibrate ddr3? 

5- should we use calibration success or calibration fail in the reset routine? 

 

regards 

drogio 

 

ps: this is a repost from ip discussion forum. but as you might know, people do not follow that forum as much as this forum. so i am posting here expecting several people saying i should not do this.[/I][/I][/I][/I]
0 Kudos
1 Reply
Altera_Forum
Honored Contributor I
35 Views

1- Should we connect the power up reset input(Input of FPGA coming from PC to global reset_n? Yes 

2- Should we use afi_reset_n output at all? Yes 

3- Should we connect the afi_reset_n output of the FPGA to global reset_n not to soft reset_n because we want to reset the PLL it is out of lock? No 

4- When should we use soft_reset_n, what is the advantage of using soft_reset_n, does it allow to recalibrate DDR3? Yes, you are right. It use to reset the memory. 

5- Should we use calibration success or calibration fail in the reset routine? No, this signal to monitor the calibration stage. 

 

Regards, 

WaiMun 

 

(This message was posted on behalf of Intel Corporation)
Reply