User Manual

Introduction to the TriFlash with SD Interface

In addition, the TriFlash host can read the device’s CID register using the READ_CID command. The CID register

is programmed during the TriFlash testing and formatting procedure, on the manufacturing floor. The TriFlash host

can only read this register and not write to it.

An internal pull-up resistor on the DAT3 line may be used for device detection (insertion/removal). The resistor can

be disconnected during data transfer (using ACMD42).

1.5.7.4. Device Status

The device status is separated into two fields: CardStatus and SD_Status.

• CardStatus is stored in a 32 bit status register which is sent as the data field in the card response to

host commands. Status register provides information about the device’s current state and completion

codes for the last host command. The card status can be explicitly read (polled) with the

SEND_STATUS command.

• SD_Status is stored in 512 bits, which are sent as a single data block after it was requested by the host

using the SD_STATUS (ACMD13) command. SD_STATUS contains extended status bits that relate

to BUS_WIDTH, security related bits and future specific applications.

1.5.7.5. Memory Array Partitioning

The basic unit of data transfer to/from the TriFlash is one byte. All data transfer operations which require a block

size always define block lengths as integer multiples of bytes. Some special functions need other partition

granularity.

For block-oriented commands, the following definition is used:

• Block—The unit that is related to the block oriented read and write commands. Its size is the number

of bytes that will be transferred when one block command is sent by the host. The size of a block is

either programmable or fixed. The information about allowed block sizes and the programmability is

stored in the CSD.

The granularity of the erasable units is in general not the same as for the block-oriented commands:

• Sector—The unit that is related to the erase commands. Its size is the number of blocks that will be

erased in one portion. The size of a sector is fixed for each device. The information about the sector

size (in blocks) is stored in the CSD.

For devices that include write protection, the following definition is used:

• WP Group—The minimal unit that may have individual write protection. Its size is the number of

groups that will be write protected by one bit. The size of a WP-group is fixed for each device. The

information about the size is stored in the CSD.