136 lines
3.4 KiB
YAML
136 lines
3.4 KiB
YAML
# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
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%YAML 1.2
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---
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$id: http://devicetree.org/schemas/memory-controllers/ddr/jedec,lpddr2-timings.yaml#
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$schema: http://devicetree.org/meta-schemas/core.yaml#
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title: LPDDR2 SDRAM AC timing parameters for a given speed-bin
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maintainers:
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- Krzysztof Kozlowski <krzk@kernel.org>
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properties:
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compatible:
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const: jedec,lpddr2-timings
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max-freq:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Maximum DDR clock frequency for the speed-bin, in Hz.
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min-freq:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Minimum DDR clock frequency for the speed-bin, in Hz.
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tCKESR:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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CKE minimum pulse width during SELF REFRESH (low pulse width during
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SELF REFRESH) in pico seconds.
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tDQSCK-max:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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DQS output data access time from CK_t/CK_c in pico seconds.
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tDQSCK-max-derated:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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DQS output data access time from CK_t/CK_c, temperature de-rated, in pico
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seconds.
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tFAW:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Four-bank activate window in pico seconds.
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tRAS-max-ns:
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description: |
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Row active time in nano seconds.
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tRAS-min:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Row active time in pico seconds.
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tRCD:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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RAS-to-CAS delay in pico seconds.
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tRPab:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Row precharge time (all banks) in pico seconds.
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tRRD:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Active bank A to active bank B in pico seconds.
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tRTP:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Internal READ to PRECHARGE command delay in pico seconds.
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tWR:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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WRITE recovery time in pico seconds.
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tWTR:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Internal WRITE-to-READ command delay in pico seconds.
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tXP:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Exit power-down to next valid command delay in pico seconds.
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tZQCL:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Long calibration time in pico seconds.
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tZQCS:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Short calibration time in pico seconds.
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tZQinit:
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$ref: /schemas/types.yaml#/definitions/uint32
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description: |
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Initialization calibration time in pico seconds.
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required:
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- compatible
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- min-freq
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- max-freq
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additionalProperties: false
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examples:
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- |
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timings {
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compatible = "jedec,lpddr2-timings";
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min-freq = <10000000>;
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max-freq = <400000000>;
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tCKESR = <15000>;
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tDQSCK-max = <5500>;
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tFAW = <50000>;
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tRAS-max-ns = <70000>;
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tRAS-min = <42000>;
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tRPab = <21000>;
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tRCD = <18000>;
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tRRD = <10000>;
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tRTP = <7500>;
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tWR = <15000>;
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tWTR = <7500>;
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tXP = <7500>;
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tZQCL = <360000>;
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tZQCS = <90000>;
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tZQinit = <1000000>;
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};
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