MC2GH256NMCA-2SA00 SAMSUNG [Samsung semiconductor], MC2GH256NMCA-2SA00 Datasheet - Page 16

• Manufacturer Part Number: MC2GH256NMCA-2SA00
• Description: SAMSUNG MultiMediaCard
• Manufacturer: SAMSUNG [Samsung semiconductor]

The MultiMediaCard bus has ten communication lines and three supply lines:
• CMD: Command is a bidirectional signal. The host and card drivers are operating in two modes,
• DAT0-7: Data lines are bidirectional signals. Host and card drivers are operating in push pull mode
• CLK: Clock is a host to card signal. CLK operates in push pull mode
• V
• V
The R
does not have to have open drain drivers, but must recognize this mode to switch on the R
resistors protecting the CMD and the DAT lines against bus floating when no card is inserted or when all card drivers are
in a high-impedance mode.
A constant current source can replace the R
and falling edges). If the host does not allow the switchable R
value is defined in the Chapter ). Consequently the maximum operating frequency in the open drain mode has to be
reduced if the used R
5.2.1 Hot Insertion and Removal
To guarantee the proper sequence of card pin connection during hot insertion, the use of either a special hot-insertion
capable card connector or an auto-detect loop on the host side (or some similar mechanism) is mandatory (see Chapter 4)
No card shall be damaged by inserting or removing a card into the MultiMediaCard bus even when the power (V
Data transfer operations are protected by CRC codes, therefore any bit changes induced by card insertion and removal
can be detected by the MultiMediaCard bus master.
The inserted card must be properly reset also when CLK carries a clock frequency f
tion to prevent card (and host) damage. Data transfer failures induced by removal/insertion are detected by the bus mas-
ter. They must be corrected by the application, which may repeat the issued command.
Revision 0.3
5.2 MultiMediaCard Bus Topology
open drain and push pull.
DD
SS1
OD
: V
, V
DD
is switched on and off by the host synchronously to the open-drain and push-pull mode transitions. The host
SS2
is the power supply line for all cards.
are two ground lines.
CMD
value is higher than the minimal one given in Table 5-5.
R
OD
Figure 5-1 : Bus Circuitry Diagram
R
OD
DAT
by achieving a better performance (constant slopes for the signal rising
C
R
1
CMD
C
16
OD
2
implementation, a fixed R
C
3
MultiMediaCard
PP
. Each card shall have power protec-
CMD
OD
. R
CMD
DAT[7:0]
CLK
MultiMediaCard
can be used (the minimum
DAT
and R
CMD
Sep.22.2005
are pull-up
DD
) is up.
TM