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MultiMediaCard Product Manual
5.0 MultiMediaCard Protocol Description
5.1
General
All
communication
MultiMediaCards
is controlled by the
(master). The host sends commands of two types:
broadcast
and
addressed
commands.
Broadcast Commands
•
Broadcast
commands
MultiMediaCards.
Some of these
require a response.
Addressed (Point-to-Point) Commands
•
The addressed commands are sent to the addressed
MultiMediaCard and cause a response from this
card.
A general overview of the command flow is shown
in Figure 5-1 for the Card Identification Mode and
in Figure 5-2 for the Data Transfer Mode. The
commands are listed in the command tables (Table
5-3 through Table 5-9). The dependencies between
the
current MultiMediaCard
command and following state are listed in Table
5-10. In the following sections, the different card
operation
modes
will
Thereafter, the restrictions for controlling t h e
clock signal are defined. All MultiMediaCard
commands together
Table 5-1 Bus Modes Overview
Card State
Inactive State
Idle State
Ready State
Identification State
Stand-by State
Transfer State
Sending-data State
Receive-data State
Programming State
Disconnect State
If a command with improper CRC was received, i t
is ignored. If there was a command execution (e.g.
38
between
the
host
host
(point-to-point)
are
intended
for
commands
state,
received
be
described
first.
with
the
corresponding
Operation Mode
Inactive
Card Identification Mode
Data Transfer Mode
SanDisk MultiMediaCard Product Manual Rev. 2 © 2000 SANDISK CORPORATION
and
responses, state transitions, error conditions and
timings are presented in the following sections.
Three
operation
MultiMediaCards:
Card Identification Mode
•
The host will be in card identification mode after
a l l
reset and while it is looking for new cards on t h e
bus. MultiMediaCards will be in this mode after
reset until the SET_RCA command (CMD3) is
received.
Interrupt Mode
•
The Interrupt Mode option defined
MultiMediaCard Standard is not implemented on
the SanDisk MultiMediaCard.
Data Transfer Mode
•
MultiMediaCards will enter data transfer mode
once an RCA is assigned to them. The host will
enter data transfer mode after identifying all t h e
MultiMediaCards on the bus.
The following table shows the dependencies
between bus modes, operation modes and card
states. Each state in the MultiMediaCard state
diagram (Figure 5-1 and Figure 5-2) is associated
with one bus mode and one operation mode:
Open-Drain
Push-Pull
continuous data read) the card continues in t h e
operation until it gets a correct host command.
modes
are
defined
in t h e
Bus Mode
for
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