xref: /freebsd/sys/contrib/device-tree/Bindings/ddr/lpddr2-timings.txt (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1* AC timing parameters of LPDDR2(JESD209-2) memories for a given speed-bin
2
3Required properties:
4- compatible : Should be "jedec,lpddr2-timings"
5- min-freq : minimum DDR clock frequency for the speed-bin. Type is <u32>
6- max-freq : maximum DDR clock frequency for the speed-bin. Type is <u32>
7
8Optional properties:
9
10The following properties represent AC timing parameters from the memory
11data-sheet of the device for a given speed-bin. All these properties are
12of type <u32> and the default unit is ps (pico seconds). Parameters with
13a different unit have a suffix indicating the unit such as 'tRAS-max-ns'
14- tRCD
15- tWR
16- tRAS-min
17- tRRD
18- tWTR
19- tXP
20- tRTP
21- tDQSCK-max
22- tFAW
23- tZQCS
24- tZQinit
25- tRPab
26- tZQCL
27- tCKESR
28- tRAS-max-ns
29- tDQSCK-max-derated
30
31Example:
32
33timings_elpida_ECB240ABACN_400mhz: lpddr2-timings@0 {
34	compatible	= "jedec,lpddr2-timings";
35	min-freq	= <10000000>;
36	max-freq	= <400000000>;
37	tRPab		= <21000>;
38	tRCD		= <18000>;
39	tWR		= <15000>;
40	tRAS-min	= <42000>;
41	tRRD		= <10000>;
42	tWTR		= <7500>;
43	tXP		= <7500>;
44	tRTP		= <7500>;
45	tCKESR		= <15000>;
46	tDQSCK-max	= <5500>;
47	tFAW		= <50000>;
48	tZQCS		= <90000>;
49	tZQCL		= <360000>;
50	tZQinit		= <1000000>;
51	tRAS-max-ns	= <70000>;
52};
53