xref: /linux/Documentation/devicetree/bindings/memory-controllers/ddr/jedec,lpddr3-timings.yaml (revision 8a1e6bb3f78f06432e095758476358d8cb63c03d)

# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
%YAML 1.2
---
$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr3-timings.yaml#
$schema: http://devicetree.org/meta-schemas/core.yaml#

title: LPDDR3 SDRAM AC timing parameters for a given speed-bin

maintainers:
  - Krzysztof Kozlowski <krzk@kernel.org>

properties:
  compatible:
    const: jedec,lpddr3-timings

  reg:
    maxItems: 1
    description: |
      Maximum DDR clock frequency for the speed-bin, in Hz.
      Property is deprecated, use max-freq.
    deprecated: true

  max-freq:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Maximum DDR clock frequency for the speed-bin, in Hz.

  min-freq:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Minimum DDR clock frequency for the speed-bin, in Hz.

  tCKE:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      CKE minimum pulse width (HIGH and LOW pulse width) in pico seconds.

  tCKESR:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      CKE minimum pulse width during SELF REFRESH (low pulse width during
      SELF REFRESH) in pico seconds.

  tFAW:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Four-bank activate window in pico seconds.

  tMRD:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Mode register set command delay in pico seconds.

  tR2R-C2C:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Additional READ-to-READ delay in chip-to-chip cases in pico seconds.

  tRAS:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Row active time in pico seconds.

  tRC:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      ACTIVATE-to-ACTIVATE command period in pico seconds.

  tRCD:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      RAS-to-CAS delay in pico seconds.

  tRFC:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Refresh Cycle time in pico seconds.

  tRPab:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Row precharge time (all banks) in pico seconds.

  tRPpb:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Row precharge time (single banks) in pico seconds.

  tRRD:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Active bank A to active bank B in pico seconds.

  tRTP:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Internal READ to PRECHARGE command delay in pico seconds.

  tW2W-C2C:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Additional WRITE-to-WRITE delay in chip-to-chip cases in pico seconds.

  tWR:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      WRITE recovery time in pico seconds.

  tWTR:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Internal WRITE-to-READ command delay in pico seconds.

  tXP:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      Exit power-down to next valid command delay in pico seconds.

  tXSR:
    $ref: /schemas/types.yaml#/definitions/uint32
    description: |
      SELF REFRESH exit to next valid command delay in pico seconds.

required:
  - compatible
  - min-freq
  - max-freq

additionalProperties: false

examples:
  - |
    lpddr3 {
        timings {
            compatible = "jedec,lpddr3-timings";
            max-freq = <800000000>;
            min-freq = <100000000>;
            tCKE = <3750>;
            tCKESR = <3750>;
            tFAW = <25000>;
            tMRD = <7000>;
            tR2R-C2C = <0>;
            tRAS = <23000>;
            tRC = <33750>;
            tRCD = <10000>;
            tRFC = <65000>;
            tRPab = <12000>;
            tRPpb = <12000>;
            tRRD = <6000>;
            tRTP = <3750>;
            tW2W-C2C = <0>;
            tWR = <7500>;
            tWTR = <3750>;
            tXP = <3750>;
            tXSR = <70000>;
        };
    };