xref: /freebsd/sys/contrib/device-tree/Bindings/ddr/lpddr3-timings.txt (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1* AC timing parameters of LPDDR3 memories for a given speed-bin.
2
3The structures are based on LPDDR2 and extended where needed.
4
5Required properties:
6- compatible : Should be "jedec,lpddr3-timings"
7- min-freq : minimum DDR clock frequency for the speed-bin. Type is <u32>
8- reg : maximum DDR clock frequency for the speed-bin. Type is <u32>
9
10Optional properties:
11
12The following properties represent AC timing parameters from the memory
13data-sheet of the device for a given speed-bin. All these properties are
14of type <u32> and the default unit is ps (pico seconds).
15- tRFC
16- tRRD
17- tRPab
18- tRPpb
19- tRCD
20- tRC
21- tRAS
22- tWTR
23- tWR
24- tRTP
25- tW2W-C2C
26- tR2R-C2C
27- tFAW
28- tXSR
29- tXP
30- tCKE
31- tCKESR
32- tMRD
33
34Example:
35
36timings_samsung_K3QF2F20DB_800mhz: lpddr3-timings@800000000 {
37	compatible	= "jedec,lpddr3-timings";
38	reg		= <800000000>; /* workaround: it shows max-freq */
39	min-freq	= <100000000>;
40	tRFC		= <65000>;
41	tRRD		= <6000>;
42	tRPab		= <12000>;
43	tRPpb		= <12000>;
44	tRCD		= <10000>;
45	tRC		= <33750>;
46	tRAS		= <23000>;
47	tWTR		= <3750>;
48	tWR		= <7500>;
49	tRTP		= <3750>;
50	tW2W-C2C	= <0>;
51	tR2R-C2C	= <0>;
52	tFAW		= <25000>;
53	tXSR		= <70000>;
54	tXP		= <3750>;
55	tCKE		= <3750>;
56	tCKESR		= <3750>;
57	tMRD		= <7000>;
58};
59