MultiMediaCard
TM
73
Sep.22.2005
Revision 0.3
Data transfer mode.
After a card receives its RCA it will switch to data transfer mode. In this mode the CMD line is driven with push-pull drivers.
The command is followed by a period of two Z bits (allowing time for direction switching on the bus) and than by P bits
pushed up by the responding card. This timing diagram is relevant for all responded host commands except CMD1,2,3:
Figure 6-9 : Command Response Timing (Data Transfer Mode)
R1b Responses
Some commands, like CMD6, may assert the BUSY signal after responding with R1. If the busy signal is asserted, it is
done two clock cycles after the end bit of the command. the DAT0 line is driven low, DAT1-DAT7 lines are driven by the
card though their value is not relevant.
Figure 6-10 : R1b Response Timing
Last Card Response - Next Host Command Timing
After receiving the last card response, the host can start the next command transmission after at least N
RC
clock cycles.
This timing is relevant for any host command.
Figure 6-11 : Timing Response End To Next Command Start (Data Transfer Mode)
Last Host Command - Next Host Command Timing
After the last command has been sent, the host can continue sending the next command after at least N
CC
clock periods.
If the ALL_SEND_CID command is not responded by the card after N
ID
+ 1 clock periods, the host can conclude there is
no card present in the bus.
Figure 6-12 : Timing Of Command Sequences (All Modes)
←
Host Command
→
←
N
CR
cycles
→
←
S T
content
CRC E Z Z P * * * P S T
Response
content
→
CRC E Z Z Z
CMD
←
Host Command
→
S T
content
CMD
CRC E Z Z Z Z Z
←
N
ST
→
←
Card Is Busy
→
Z Z Z Z Z Z Z Z Z Z Z Z S L
Z Z Z Z Z Z Z Z Z Z Z Z X
* * * * * * * * * * * * * * * * * * * * * * * *
* * * * * * * * * * * * * * * * * * * *
Z Z Z Z Z
DAT0
DAT1-7
* * * * * * * * * * * * * * * * * * * * * *
E Z Z Z
X Z Z Z
←
Response
→
←
N
CR
cycles
→
←
Host Command
→
S T
content
CRC E Z
* * *
CMD
Z S T
content
CRC E Z Z
←
Host Command
→
←
N
CC
cycles
→
←
Host Command
→
S T
content
CRC E Z
* * *
CMD
Z S T
content
CRC E Z Z