HB28E016MM2 Hitachi Semiconductor, HB28E016MM2 Datasheet - Page 22

• Manufacturer Part Number: HB28E016MM2
• Description: (HB28D032MM2 / HB28D016MM2 / HB28E016MM2 /HB28B128MM2) MultiMediaCard 16 Mbyte/32 Mbyte/64 Mbyte/128 MByte
• Manufacturer: Hitachi Semiconductor

HB28E016/D032/D064/B128MM2
MultiMediaCard Communication
All communication between host and cards is controlled by the host (master). The host sends commands
and, depending on the command, receives a corresponding response from the selected card. In this chapter
the commands to control these Hitachi MultiMediaCards, the card responses and the contents of the status
and error field included in the responses, are defined.
Memory Array Partitioning
The basic unit of data transfer to/from the MultiMediaCard 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:
For devices which have erasable memory cells, special erase commands are defined. The granularity of the
erasable units is:
For devices which include a write protection:
Each erasable unit (erase group and sector) has a special “tag” bit. This bit may be set or cleared by special
commands to tag the unit. All tagged units will be erased in parallel by one erase command following a
number of tag commands. All tag bits are cleared by each command except a tag or untag command.
Therefore, immediately after a sequence of tag commands an erase command has to be sent by the host.
Commands others than tagging or erasing abort a tag-erase cycle irregularly.
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Block: is the unit which is related to the block-oriented read and write commands. Its size is the
number of bytes which 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.
Sector: is the unit which is related to the tagged sector commands (CMD32 to CMD34). In these
Hitachi MultiMediaCards, this size is same as the WRITE_BLK_LEN in CSD.
Erase Group: is the smallest number of consecutive write blocks, which can be addressed for erased.
The size of the Erase Group is card specific and stored in the CSD.
WP-Group: is the minimal unit which may have individual write protection. Its size is the number of
erase groups which 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.