xref: /freebsd-src/sys/contrib/device-tree/Bindings/ddr/lpddr2-timings.txt (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
1*c66ec88fSEmmanuel Vadot* AC timing parameters of LPDDR2(JESD209-2) memories for a given speed-bin
2*c66ec88fSEmmanuel Vadot
3*c66ec88fSEmmanuel VadotRequired properties:
4*c66ec88fSEmmanuel Vadot- compatible : Should be "jedec,lpddr2-timings"
5*c66ec88fSEmmanuel Vadot- min-freq : minimum DDR clock frequency for the speed-bin. Type is <u32>
6*c66ec88fSEmmanuel Vadot- max-freq : maximum DDR clock frequency for the speed-bin. Type is <u32>
7*c66ec88fSEmmanuel Vadot
8*c66ec88fSEmmanuel VadotOptional properties:
9*c66ec88fSEmmanuel Vadot
10*c66ec88fSEmmanuel VadotThe following properties represent AC timing parameters from the memory
11*c66ec88fSEmmanuel Vadotdata-sheet of the device for a given speed-bin. All these properties are
12*c66ec88fSEmmanuel Vadotof type <u32> and the default unit is ps (pico seconds). Parameters with
13*c66ec88fSEmmanuel Vadota different unit have a suffix indicating the unit such as 'tRAS-max-ns'
14*c66ec88fSEmmanuel Vadot- tRCD
15*c66ec88fSEmmanuel Vadot- tWR
16*c66ec88fSEmmanuel Vadot- tRAS-min
17*c66ec88fSEmmanuel Vadot- tRRD
18*c66ec88fSEmmanuel Vadot- tWTR
19*c66ec88fSEmmanuel Vadot- tXP
20*c66ec88fSEmmanuel Vadot- tRTP
21*c66ec88fSEmmanuel Vadot- tDQSCK-max
22*c66ec88fSEmmanuel Vadot- tFAW
23*c66ec88fSEmmanuel Vadot- tZQCS
24*c66ec88fSEmmanuel Vadot- tZQinit
25*c66ec88fSEmmanuel Vadot- tRPab
26*c66ec88fSEmmanuel Vadot- tZQCL
27*c66ec88fSEmmanuel Vadot- tCKESR
28*c66ec88fSEmmanuel Vadot- tRAS-max-ns
29*c66ec88fSEmmanuel Vadot- tDQSCK-max-derated
30*c66ec88fSEmmanuel Vadot
31*c66ec88fSEmmanuel VadotExample:
32*c66ec88fSEmmanuel Vadot
33*c66ec88fSEmmanuel Vadottimings_elpida_ECB240ABACN_400mhz: lpddr2-timings@0 {
34*c66ec88fSEmmanuel Vadot	compatible	= "jedec,lpddr2-timings";
35*c66ec88fSEmmanuel Vadot	min-freq	= <10000000>;
36*c66ec88fSEmmanuel Vadot	max-freq	= <400000000>;
37*c66ec88fSEmmanuel Vadot	tRPab		= <21000>;
38*c66ec88fSEmmanuel Vadot	tRCD		= <18000>;
39*c66ec88fSEmmanuel Vadot	tWR		= <15000>;
40*c66ec88fSEmmanuel Vadot	tRAS-min	= <42000>;
41*c66ec88fSEmmanuel Vadot	tRRD		= <10000>;
42*c66ec88fSEmmanuel Vadot	tWTR		= <7500>;
43*c66ec88fSEmmanuel Vadot	tXP		= <7500>;
44*c66ec88fSEmmanuel Vadot	tRTP		= <7500>;
45*c66ec88fSEmmanuel Vadot	tCKESR		= <15000>;
46*c66ec88fSEmmanuel Vadot	tDQSCK-max	= <5500>;
47*c66ec88fSEmmanuel Vadot	tFAW		= <50000>;
48*c66ec88fSEmmanuel Vadot	tZQCS		= <90000>;
49*c66ec88fSEmmanuel Vadot	tZQCL		= <360000>;
50*c66ec88fSEmmanuel Vadot	tZQinit		= <1000000>;
51*c66ec88fSEmmanuel Vadot	tRAS-max-ns	= <70000>;
52*c66ec88fSEmmanuel Vadot};
53