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freebsd
GitHub Repository: freebsd/freebsd-src
 Path: blob/main/sys/contrib/device-tree/Bindings/ddr/lpddr2-timings.txt
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* AC timing parameters of LPDDR2(JESD209-2) memories for a given speed-bin

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Required properties:

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- compatible : Should be "jedec,lpddr2-timings"

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- min-freq : minimum DDR clock frequency for the speed-bin. Type is <u32>

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- max-freq : maximum DDR clock frequency for the speed-bin. Type is <u32>

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Optional properties:

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The following properties represent AC timing parameters from the memory

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data-sheet of the device for a given speed-bin. All these properties are

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of type <u32> and the default unit is ps (pico seconds). Parameters with

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a different unit have a suffix indicating the unit such as 'tRAS-max-ns'

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- tRCD

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- tWR

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- tRAS-min

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- tRRD

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- tWTR

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- tXP

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- tRTP

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- tDQSCK-max

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- tFAW

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- tZQCS

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- tZQinit

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- tRPab

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- tZQCL

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- tCKESR

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- tRAS-max-ns

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- tDQSCK-max-derated

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Example:

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timings_elpida_ECB240ABACN_400mhz: lpddr2-timings@0 {

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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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	tRPab		= <21000>;

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	tRCD		= <18000>;

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	tWR		= <15000>;

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	tRAS-min	= <42000>;

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	tRRD		= <10000>;

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	tWTR		= <7500>;

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	tXP		= <7500>;

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	tRTP		= <7500>;

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	tCKESR		= <15000>;

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	tDQSCK-max	= <5500>;

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	tFAW		= <50000>;

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	tZQCS		= <90000>;

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	tZQCL		= <360000>;

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	tZQinit		= <1000000>;

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	tRAS-max-ns	= <70000>;

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};

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