xref: /linux/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3-timings.yaml (revision 0526b56cbc3c489642bd6a5fe4b718dea7ef0ee8) 
1# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2%YAML 1.2
3---
4$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr3-timings.yaml#
5$schema: http://devicetree.org/meta-schemas/core.yaml#
6
7title: LPDDR3 SDRAM AC timing parameters for a given speed-bin
8
9maintainers:
10  - Krzysztof Kozlowski <krzk@kernel.org>
11
12properties:
13  compatible:
14    const: jedec,lpddr3-timings
15
16  reg:
17    maxItems: 1
18    description: |
19      Maximum DDR clock frequency for the speed-bin, in Hz.
20      Property is deprecated, use max-freq.
21    deprecated: true
22
23  max-freq:
24    $ref: /schemas/types.yaml#/definitions/uint32
25    description: |
26      Maximum DDR clock frequency for the speed-bin, in Hz.
27
28  min-freq:
29    $ref: /schemas/types.yaml#/definitions/uint32
30    description: |
31      Minimum DDR clock frequency for the speed-bin, in Hz.
32
33  tCKE:
34    $ref: /schemas/types.yaml#/definitions/uint32
35    description: |
36      CKE minimum pulse width (HIGH and LOW pulse width) in pico seconds.
37
38  tCKESR:
39    $ref: /schemas/types.yaml#/definitions/uint32
40    description: |
41      CKE minimum pulse width during SELF REFRESH (low pulse width during
42      SELF REFRESH) in pico seconds.
43
44  tFAW:
45    $ref: /schemas/types.yaml#/definitions/uint32
46    description: |
47      Four-bank activate window in pico seconds.
48
49  tMRD:
50    $ref: /schemas/types.yaml#/definitions/uint32
51    description: |
52      Mode register set command delay in pico seconds.
53
54  tR2R-C2C:
55    $ref: /schemas/types.yaml#/definitions/uint32
56    description: |
57      Additional READ-to-READ delay in chip-to-chip cases in pico seconds.
58
59  tRAS:
60    $ref: /schemas/types.yaml#/definitions/uint32
61    description: |
62      Row active time in pico seconds.
63
64  tRC:
65    $ref: /schemas/types.yaml#/definitions/uint32
66    description: |
67      ACTIVATE-to-ACTIVATE command period in pico seconds.
68
69  tRCD:
70    $ref: /schemas/types.yaml#/definitions/uint32
71    description: |
72      RAS-to-CAS delay in pico seconds.
73
74  tRFC:
75    $ref: /schemas/types.yaml#/definitions/uint32
76    description: |
77      Refresh Cycle time in pico seconds.
78
79  tRPab:
80    $ref: /schemas/types.yaml#/definitions/uint32
81    description: |
82      Row precharge time (all banks) in pico seconds.
83
84  tRPpb:
85    $ref: /schemas/types.yaml#/definitions/uint32
86    description: |
87      Row precharge time (single banks) in pico seconds.
88
89  tRRD:
90    $ref: /schemas/types.yaml#/definitions/uint32
91    description: |
92      Active bank A to active bank B in pico seconds.
93
94  tRTP:
95    $ref: /schemas/types.yaml#/definitions/uint32
96    description: |
97      Internal READ to PRECHARGE command delay in pico seconds.
98
99  tW2W-C2C:
100    $ref: /schemas/types.yaml#/definitions/uint32
101    description: |
102      Additional WRITE-to-WRITE delay in chip-to-chip cases in pico seconds.
103
104  tWR:
105    $ref: /schemas/types.yaml#/definitions/uint32
106    description: |
107      WRITE recovery time in pico seconds.
108
109  tWTR:
110    $ref: /schemas/types.yaml#/definitions/uint32
111    description: |
112      Internal WRITE-to-READ command delay in pico seconds.
113
114  tXP:
115    $ref: /schemas/types.yaml#/definitions/uint32
116    description: |
117      Exit power-down to next valid command delay in pico seconds.
118
119  tXSR:
120    $ref: /schemas/types.yaml#/definitions/uint32
121    description: |
122      SELF REFRESH exit to next valid command delay in pico seconds.
123
124required:
125  - compatible
126  - min-freq
127  - max-freq
128
129additionalProperties: false
130
131examples:
132  - |
133    lpddr3 {
134        timings {
135            compatible = "jedec,lpddr3-timings";
136            max-freq = <800000000>;
137            min-freq = <100000000>;
138            tCKE = <3750>;
139            tCKESR = <3750>;
140            tFAW = <25000>;
141            tMRD = <7000>;
142            tR2R-C2C = <0>;
143            tRAS = <23000>;
144            tRC = <33750>;
145            tRCD = <10000>;
146            tRFC = <65000>;
147            tRPab = <12000>;
148            tRPpb = <12000>;
149            tRRD = <6000>;
150            tRTP = <3750>;
151            tW2W-C2C = <0>;
152            tWR = <7500>;
153            tWTR = <3750>;
154            tXP = <3750>;
155            tXSR = <70000>;
156        };
157    };
158