All SD cards let the host accessory actuate how abundant advice the agenda can hold, and the blueprint of anniversary SD ancestors gives the host accessory a agreement of the best accommodation a adjustable agenda will report.
By the time the Adaptation 2.0 (SDHC) blueprint was completed in June 2006,61 vendors had already devised 2 GB and 4 GB SD cards, either as defined in Adaptation 1.01, or by creatively account Adaptation 1.00. The consistent cards do not plan accurately in some host devices.6263
edit SDSC cards aloft 1 GB
4 GB SDSC card
A host accessory can ask any amid SD agenda for its 128-bit identification cord (the Card-Specific Abstracts or CSD). In standard-capacity cards (SDSC), 12 $.25 analyze the amount of anamnesis clusters (ranging from 1 to 4,096) and 3 $.25 analyze the amount of blocks per array (which break to 4, 8, 16, 32, 64, 128, 256, or 512 blocks per cluster). The host accessory multiplies these abstracts (as apparent in the afterward section) with the amount of bytes per block to actuate the card's accommodation in bytes.
In SD adaptation 1.00, the amount of bytes per block was affected to be 512. This acceptable SDSC cards up to 4,096 × 512 × 512 = 1 GB, for which there are no accepted incompatibilities.
Version 1.01 let an SDSC agenda use a 4-bit acreage to announce 1,024 or 2,048 bytes per block instead.39 Doing so enabled cards with 2 GB and 4 GB capacity.
Early SDSC host accessories that accept 512-byte blocks accordingly will not absolutely abutment the admittance of 2 GB or 4 GB cards. In some cases, the host accessory can apprehend abstracts that happens to abide in the aboriginal 1 GB of the card. If the acceptance is fabricated in the disciplinarian software, success may alter from one adaptation of Windows to another. In addition, any host accessory ability not abutment a 4 GB SDSC card, back the blueprint lets it accept that 2 GB is the best for these cards.
edit Storage accommodation calculations
The architecture of the Card-Specific Abstracts (CSD) annals afflicted amid adaptation 1 (SDSC) and adaptation 2.0 (which defines SDHC and SDXC).
Version 1
In Adaptation 1 of the SD specification, accommodation is affected by accumulation fields of the CSD as follows:
Capacity=(C_SIZE+1)<<(C_SIZE_MULT+2)<<="" p="">
Where 0<=C_SIZE<=4095, 0<=C_SIZE_MULT<=7, READ_BL_LEN==9 || READ_BL_LEN==10
Later versions accompaniment (at Area 4.3.2) that a 2 GB SDSC agenda shall set its READ_BL_LEN (and WRITE_BL_LEN) to announce 1024 bytes, so that the aloft ciphering accurately letters the card's capacity; but that, for consistency, the host accessory shall not appeal (by CMD16) block lengths over 512 bytes.39
Versions 2 and 3
In the analogue of SDHC cards in Adaptation 2.0, the C_SIZE allocation of the CSD is 22 $.25 and it indicates the anamnesis admeasurement in multiples of 512 KB. (The C_SIZE_MULT acreage is removed and READ_BL_LEN is no best acclimated to compute capacity.) Two $.25 that were aforetime aloof now analyze the agenda family: 0 is SDSC; 1 is SDHC or SDXC; 2 and 3 are reserved.39 Because of these redefinitions, earlier host accessories do not accurately analyze SDHC or SDXC cards nor their actual capacity.
SDHC cards are belted to advertisement a accommodation not over 32 GiB.
SDXC cards are accustomed to use all 22 $.25 of the C_SIZE field. An SDHC agenda that did so (reported C_SIZE > 65375 to announce a accommodation of over 32 GiB) would breach the specification. A host accessory that relied on C_SIZE rather than the blueprint to actuate the card's best accommodation ability abutment such a card, but the agenda ability abort in added SDHC-compatible host devices.
Capacity is affected thus:
Capacity=(C_SIZE+1)*524288
where for SDHC 4112<=C_SIZE<=65375 (approx. 2 GB) < accommodation < 32 GiB
for SDXC 65535<=C_SIZE 32 GiB <= accommodation <= 2 TiB max.
Capacities aloft 4 GB can alone be accomplished by afterward Adaptation 2.0 or after versions. In addition, capacities according to 4 GB have to aswell do so to agreement compatibility.
By the time the Adaptation 2.0 (SDHC) blueprint was completed in June 2006,61 vendors had already devised 2 GB and 4 GB SD cards, either as defined in Adaptation 1.01, or by creatively account Adaptation 1.00. The consistent cards do not plan accurately in some host devices.6263
edit SDSC cards aloft 1 GB
4 GB SDSC card
A host accessory can ask any amid SD agenda for its 128-bit identification cord (the Card-Specific Abstracts or CSD). In standard-capacity cards (SDSC), 12 $.25 analyze the amount of anamnesis clusters (ranging from 1 to 4,096) and 3 $.25 analyze the amount of blocks per array (which break to 4, 8, 16, 32, 64, 128, 256, or 512 blocks per cluster). The host accessory multiplies these abstracts (as apparent in the afterward section) with the amount of bytes per block to actuate the card's accommodation in bytes.
In SD adaptation 1.00, the amount of bytes per block was affected to be 512. This acceptable SDSC cards up to 4,096 × 512 × 512 = 1 GB, for which there are no accepted incompatibilities.
Version 1.01 let an SDSC agenda use a 4-bit acreage to announce 1,024 or 2,048 bytes per block instead.39 Doing so enabled cards with 2 GB and 4 GB capacity.
Early SDSC host accessories that accept 512-byte blocks accordingly will not absolutely abutment the admittance of 2 GB or 4 GB cards. In some cases, the host accessory can apprehend abstracts that happens to abide in the aboriginal 1 GB of the card. If the acceptance is fabricated in the disciplinarian software, success may alter from one adaptation of Windows to another. In addition, any host accessory ability not abutment a 4 GB SDSC card, back the blueprint lets it accept that 2 GB is the best for these cards.
edit Storage accommodation calculations
The architecture of the Card-Specific Abstracts (CSD) annals afflicted amid adaptation 1 (SDSC) and adaptation 2.0 (which defines SDHC and SDXC).
Version 1
In Adaptation 1 of the SD specification, accommodation is affected by accumulation fields of the CSD as follows:
Capacity=(C_SIZE+1)<<(C_SIZE_MULT+2)<<="" p="">
Where 0<=C_SIZE<=4095, 0<=C_SIZE_MULT<=7, READ_BL_LEN==9 || READ_BL_LEN==10
Later versions accompaniment (at Area 4.3.2) that a 2 GB SDSC agenda shall set its READ_BL_LEN (and WRITE_BL_LEN) to announce 1024 bytes, so that the aloft ciphering accurately letters the card's capacity; but that, for consistency, the host accessory shall not appeal (by CMD16) block lengths over 512 bytes.39
Versions 2 and 3
In the analogue of SDHC cards in Adaptation 2.0, the C_SIZE allocation of the CSD is 22 $.25 and it indicates the anamnesis admeasurement in multiples of 512 KB. (The C_SIZE_MULT acreage is removed and READ_BL_LEN is no best acclimated to compute capacity.) Two $.25 that were aforetime aloof now analyze the agenda family: 0 is SDSC; 1 is SDHC or SDXC; 2 and 3 are reserved.39 Because of these redefinitions, earlier host accessories do not accurately analyze SDHC or SDXC cards nor their actual capacity.
SDHC cards are belted to advertisement a accommodation not over 32 GiB.
SDXC cards are accustomed to use all 22 $.25 of the C_SIZE field. An SDHC agenda that did so (reported C_SIZE > 65375 to announce a accommodation of over 32 GiB) would breach the specification. A host accessory that relied on C_SIZE rather than the blueprint to actuate the card's best accommodation ability abutment such a card, but the agenda ability abort in added SDHC-compatible host devices.
Capacity is affected thus:
Capacity=(C_SIZE+1)*524288
where for SDHC 4112<=C_SIZE<=65375 (approx. 2 GB) < accommodation < 32 GiB
for SDXC 65535<=C_SIZE 32 GiB <= accommodation <= 2 TiB max.
Capacities aloft 4 GB can alone be accomplished by afterward Adaptation 2.0 or after versions. In addition, capacities according to 4 GB have to aswell do so to agreement compatibility.
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