SanDisk SD032 Manual descarregar pdf (Página 15)

1.5.9.9. Erase

The smallest erasable unit in the miniSD Card is a sector. In order to speed up the erase procedure, multiple sectors

can be erased at the same time. To facilitate selection, a first command with the starting address is followed by a

second command with the final address, and all sectors within this range will be selected for erase.

1.5.9.10. Write Protection

Two-card level write-protection options are available: permanent and temporary. Both can be set using the

PROGRAM_CSD command (see below). The permanent write protect bit, once set, cannot be cleared. This feature

is implemented in the miniSD Card controller firmware and not with a physical OTP cell.

NOTE: Use the Write Protect (WP) Switch located on the card’s side edge to prevent the host from writing to or

erasing data on the card. The WP switch does not have any influence on the internal Permanent or

Temporary WP bits in the CSD.

1.5.9.11. Copy Bit

The content of a miniSD Card can be marked as an original or a copy using the copy bit in the CSD register. Once

the Copy bit is set (marked as a copy) it cannot be cleared. The Copy bit of the miniSD Card is programmed (during

test and formatting on the manufacturing floor) as a copy. The miniSD Card can be purchased with the copy bit set

(copy) or cleared, indicating the card is a master. This feature is implemented in the miniSD Card controller

firmware and not with a physical OTP cell.

1.5.9.12. The CSD Register

All the configuration information of the miniSD Card is stored in the CSD register. The MSB bytes of the register

contain manufacturer data and the two least significant bytes contain the host-controlled data, the card Copy, write

protection and the user file format indication.

The host can read the CSD register and alter the host controlled data bytes using the SEND_CSD and

PROGRAM_CSD commands.

1.5.10. miniSD Card—SPI Mode

The SPI mode is a secondary communication protocol for miniSD Cards. This mode is a subset of the miniSD Card

protocol, designed to communicate with an SPI channel, commonly found in Motorola’s (and lately a few other

vendors’) microcontrollers.

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