1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
* AC timing parameters of LPDDR2(JESD209-2) memories for a given speed-bin
Required properties:
- compatible : Should be "jedec,lpddr2-timings"
- min-freq : minimum DDR clock frequency for the speed-bin. Type is <u32>
- max-freq : maximum DDR clock frequency for the speed-bin. Type is <u32>
Optional properties:
The following properties represent AC timing parameters from the memory
data-sheet of the device for a given speed-bin. All these properties are
of type <u32> and the default unit is ps (pico seconds). Parameters with
a different unit have a suffix indicating the unit such as 'tRAS-max-ns'
- tRCD
- tWR
- tRAS-min
- tRRD
- tWTR
- tXP
- tRTP
- tDQSCK-max
- tFAW
- tZQCS
- tZQinit
- tRPab
- tZQCL
- tCKESR
- tRAS-max-ns
- tDQSCK-max-derated
Example:
timings_elpida_ECB240ABACN_400mhz: lpddr2-timings@0 {
compatible = "jedec,lpddr2-timings";
min-freq = <10000000>;
max-freq = <400000000>;
tRPab = <21000>;
tRCD = <18000>;
tWR = <15000>;
tRAS-min = <42000>;
tRRD = <10000>;
tWTR = <7500>;
tXP = <7500>;
tRTP = <7500>;
tCKESR = <15000>;
tDQSCK-max = <5500>;
tFAW = <50000>;
tZQCS = <90000>;
tZQCL = <360000>;
tZQinit = <1000000>;
tRAS-max-ns = <70000>;
};
|
