User manual TRANSCEND TS8GJFT3W

[. . . ] The OCR, CID, CSD and SCR registers carry the card/content specific information, while the RCA and DSR registers are configuration registers storing actual configuration parameters. 1. OCR register The 32-bit operation conditions register stores the VDD voltage profile of the card. One status bit is set if the card power up procedure has been finished. This register includes another status bit indicating the card capacity status after set power up status bit. [. . . ] Bit 31 - Card power up status bit, this status bit is set if the card power up procedure has been finished. Bit 30 - Card capacity status bit, this status bit is set to 1 if card is High Capacity SD Memory Card. The Card Capacity status bit is valid after the card power up procedure is completed and the card power up status bit is set to 1. The Host shall read this status bit to identify a Standard or High Capacity SD Memory Card. The OCR register shall be implemented by the cards. OCR Register Definition Transcend Information Inc. 11 SDHC Card seriies SDHC Card ser es 4~32GB High Capacity Secure Digital Card 1) This bit is valid only when the card power up status bit is set. 2) This bit is set to LOW if the card has not finished the power up routine. A voltage range is not supported if the corresponding bit value is set to LOW. As long as the card is busy, the corresponding bit (31) is set to LOW. 2. CID Register The Card IDentification (CID) register is 128 bits wide. It contains the card identification information used during the card identification phase. Every individual flash card shall have a unique identification number. 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. Transcend Information Inc. 17 SDHC Card seriies SDHC Card ser es · COPY 4~32GB High Capacity Secure Digital Card Defines if the contents is original (= `0') or has been copied (='1'). The COPY bit for OTP and MTPdevices, sold to end consumers, is set to `1' which identifies the card contents as a copy. The COPY bit is an one time programmable bit. · PERM_WRITE_PROTECT Permanently protects the whole card content against overwriting or erasing (all write and erase commands for this card are permanently disabled). not permanently write protected. · TMP_WRITE_PROTECT Temporarily protects the whole card content from being overwritten or erased (all write and erase commands for this card are temporarily disabled). Host should not use this field. · CRC The CRC field carries the check sum for the CSD contents. The checksum has to be recalculated by the host for any CSD modification. The following table lists the correspondence between the CSD entries and the command classes. A `+' entry indicates that the CSD field affects the commands of the related command class. Transcend Information Inc. 18 SDHC Card seriies SDHC Card ser es 4~32GB High Capacity Secure Digital Card 4. RCA Register The writable 16-bit relative card address register carries the card address that is published by the card during the card identification. [. . . ] The value0x0000 is reserved to set all cards into the Stand-by State with CMD7. 5. DSR Register (Optional) The 16-bit driver stage register is described in detail in Chapter 6. 5. It can be optionally used to improve the bus performance for extended operating conditions (depending on parameters like bus length, transfer rate or number of cards). The CSD register carries the information about the DSR register usage. [. . . ]