SDHC Card series
4~32GB High Capacity Secure Digital Card
•C_SIZE
This field is expanded to 22 bits and can indicate up to 2 TBytes (It is the same as the maximum memory space specified by a
This parameter is used to calculate the user data area capacity in the SD memory card (not include the protected area). The user data area capacity is calculated from C_SIZE as follows: memory capacity = (C_SIZE+1) * 512K byte
As the maximum capacity of the Physical Layer Specification Version 2.00 is 32 GB, the upper 6 bits of this field shall be set to 0.
•ERASE_BLK_EN
This field is fixed to 1, which means the host can erase one or multiple units of 512 bytes.
•SECTOR_SIZE
This field is fixed to 7Fh, which indicates 64 KBytes. This value does not relate to erase operation. Version 2.00 cards indicates memory boundary by AU size and this field should not be used.
•WP_GRP_SIZE
This field is fixed to 00h. The High Capacity SD Memory Card does not support write protected groups.
•WP_GRP_ENABLE
This field is fixed to 0. The High Capacity SD Memory Card does not support write protected groups.
•R2W_FACTOR
This field is fixed to 2h, which indicates 4 multiples. Write timeout can be calculated by multiplying the read access time and R2W_FACTOR. However, the host should not use this factor and should use 250 ms for write timeout
•WRITE_BL_LEN
This field is fixed to 9h, which indicates WRITE_BL_LEN=512 Byte.
•WRITE_BL_PARTIAL
This field is fixed to 0, which indicates partial block read is inhibited and only unit of block access is allowed.
•FILE_FORMAT_GRP
This field is set to 0. Host should not use this field.
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