JEDEC Standard No. 79-4B
-i-
1 Scope ............................................................................................................................................................................1
2 DDR4 SDRAM Package Pinout and Addressing ......................................................................................................2
2.1 DDR4 SDRAM Row for X4, X8 and X16..........................................
.............................................................................2
2.2 DDR4 SDRAM Ball Pitch ...............................................................
................................................................................2
2.3 DDR4 SDRAM Columns for X4,X8 and X16..........................................
........................................................................2
2.4 DDR4 SDRAM X4/8 Ballout using MO-207 ......................................
.......................................................................... 2
2.5 DDR4 SDRAM X16 Ballout using MO-207 .......................................
.............................................................................3
2.6 DDR4 SDRAM X32 Ballout using MO-XXX ..............................................
.....................................................................4
2.7 Pinout Description.................................................................
.........................................................................................6
2.8 DDR4 SDRAM Addressing................................................................
.............................................................................7
2.9 DDP Single Rank(SR) x16 from two x8 .................................................
........................................................................9
3 Functional Description .............................................................................................................................................11
3.1 Simplified State Diagram ......................................................
.................................................................................... 11
3.2 Basic Functionality ................................................................
.......................................................................................12
3.3 RESET and Initialization Procedure...............................................
..............................................................................12
3.3.1 Power-up Initialization Sequence .......................................
.......................................................................................12
3.3.2 VDD Slew rate at Power-up Initialization Sequence .................................................................................................13
3.3.3 Reset Initialization with Stable Power .......................................................................................................................14
3.4 Register Definition........................................................................................................................................................14
3.4.1 Programming the mode registers ..............................................................................................................................14
3.5 Mode Register.......................................................................
.......................................................................................17
4 DDR4 SDRAM Command Description and Operation ...........................................................................................28
4.1 Command Truth Table.................................................................
.................................................................................28
4.2 CKE Truth Table ....................................................................
.......................................................................................29
4.3 Burst Length, Type and Order........................................................
..............................................................................30
4.3.1 BL8 Burst order with CRC Enabled ................................................
...........................................................................30
4.4 DLL-off Mode & DLL on/off Switching procedure....................
....................................................................................31
4.4.1 DLL on/off switching procedure .................................................................................................................................31
4.4.2 DLL “on” to DLL “off” Procedure ................................................................................................................................31
4.4.3 DLL “off” to DLL “on” Procedure ................................................................................................................................32
4.5 DLL-off Mode ...............................................................................................................................................................33
4.6 Input Clock Frequency Change ........................................................
...........................................................................34
4.7 Write Leveling .....................................................................
.........................................................................................35
4.7.1 DRAM setting for write leveling & DRAM termination function in that mode .............................................................36
4.7.2 Procedure Description................................................................................................................................................36
4.7.3 Write Leveling Mode Exit............................................................................................................................................37
4.8 Temperature controlled Refresh modes.......................................................................................................................38
4.8.1 Normal temperature mode ( 0°C =< TCASE =< 85°C ) ............................................................................................38
4.8.2 Extended temperature mode ( 0°C =< TCASE =< 95°C ) .........................................................................................38
4.9 Fine Granularity Refresh Mode......................................................
..............................................................................39
4.9.1 Mode Register and Command Truth Table...........
.....................................................................................................39
4.9.2 tREFI and tRFC parameters.......................................................................................................................................40
4.9.3 Changing Refresh Rate..............................................................................................................................................40
4.9.4 Usage with Temperature Controlled Refresh mode...................................................................................................41
4.9.5 Self Refresh entry and exit.........................................................................................................................................41
4.10 Multi Purpose Register................................................................................................................................................41
4.10.1 DQ Training with MPR..............................................................................................................................................41
4.10.2 MR3 definition .........................................................................................................................................................41
4.10.3 MPR Reads .............................................................................................................................................................42
4.10.4 MPR Writes .............................................................................................................................................................44
4.10.5 MPR Read Data format ...........................................................................................................................................47
4.11 Data Mask(DM), Data Bus Inversion (DBI) and TDQS....
............................................................................................52
DDR4 SDRAM STANDARD
Contents
评论0
最新资源