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SDRAM core parameters

Altera_Forum
Honored Contributor II
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Hi all  

 

In my board i use SDRAM k4s561632E-tc75 -  

it have 256Mbit size  

Datawidth 16  

Banks -4  

Row 13  

Col 9  

I use 2 chips so 2 Chip selects  

 

I have verilog behaviour model of it  

And it has next timing parameters  

`define tCCmin 7.5 // clock minimum cycle time 

`define tCCmax 1000 // clock maximun cycle time 

`define tCC3 7.5 // clock minimun cycle time at cas latency=3 

`define tCC2 10 // clock minimun cycle time at cas latency=2 

`define tCH 2.5 // clock high pulse width 

`define tCL 2.5 // clock low pulse width 

`define tSS 1.5 // input setup time 

`define tSH 0.8 // input hold time 

`define tRRD 15 // row to row delay(min) 

`define tRCD 20 // ras to cas delay(min) 

`define tRP 20 // row precharge time(min) 

`define tRASmin 45 // row active minimum time 

`define tRASmax 100000 // row active maximum time 

`define tRC 65 // row cycle time(min) 

`define tCCD 7.5 // col. address to col. address delay: 

`define tSAC2 6 

`define tSAC3 5.4 

`define tSHZ2 6 

`define tSHZ3 5.4 

 

And i can't find correspondence with SOPC SDRAM parameters  

i'm know how SDRAM works in idea only and i don't know how exactly it working  

so can someone help me to find correspondence with next parameters, please  

 

Cas latency cycles 3 (it's looks correct ) 

Initialization refresh cycles 7 (i assign big value but may be i'ts incorrect) 

Issue one refresh commant every 7.8125 (i set it like 64ms/8192 cyles so it looks correct ) 

Delay after powerup,before initialization 100 us (not changes ) 

Duration of refresh command (t_rfc) 80 (don't know ) 

Duration of precharge command (t_rp) 20 (don't know ) 

ACTIVE to READ or WRITE delay (t_rcd) 20 (don't know ) 

Access time (t_ac) 6 (don't know ) 

Write recovery time (t_wr, NoautoPrecharge) 20 (i don't know) 

 

Can someone correct my parameters or tell how and where get it , because i saw datasheets  

and i did't saw that paramereres in clear form.
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