Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3-timings.yaml

   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
   7 title: LPDDR3 SDRAM AC timing parameters for a given speed-bin
   8
   9 maintainers:
  10   - Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
  11
  12 properties:
  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
 124 required:
 125   - compatible
 126   - min-freq
 127   - max-freq
 128
 129 additionalProperties: false
 130
 131 examples:
 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     };