Timings; 5.10.1 Command And Response - SanDisk SDMB-16-470 - 16 MB MultiMedia Card Product Manual

MultiMediaCard Product Manual
5.10

Timings

All timing diagrams use the following schematics and abbreviations:
Table 5-11 Timing Diagram Symbols
The difference between the P-bit and Z-bit is that a P-bit is actively driven to HIGH by the card
respectively host output driver, while Z-bit is driven to (respectively kept) HIGH by the pull-up
resistors R respectively R
CMD
All timing values are defined in Table 5-12.

5.10.1 Command and Response

Both host command and card response are clocked out with the rising edge of the host clock. The
minimum delay between the host command and card response is N
relevant for host command CMD3.
<---- Host Command ---->
CMD S T Content
Figure 5-5 Command Response Timing (Identification Mode)
There is just one Z bit period followed by P bits pushed up by the responding card. This timing diagram
is relevant for all responded host commands except CMD1,2,3.
<---- Host Command ---->
CMD S T Content
Figure 5-6 Command Response Timing (Data Transfer Mode)
56
S
T Transmitter Bit (Host = 1, Card = 0)
P One-cycle Pull-up (= 1)
E
Z High Impedance State (-> = 1)
D
*
CRC Cyclic Redundancy Check Bits (7 Bits)
. Actively-driven P-bits are less sensitive to noise superposition.
DAT
<-NCR Cycles->
CRC E Z
* * * * * *
<-N Cycles->
CR
CRC E Z Z P * * *
SanDisk MultiMediaCard Product Manual Rev. 2 © 2000 SANDISK CORPORATION
Start Bit (= 0)
End Bit (=1)
Data Bits
Repeater
Card Active
Host Active
clock cycles. This timing diagram is
CR
<-------- Response --------->
Z S T Content CRC E
<-------- Response --------->
P S T Content CRC E
Z Z Z
Z Z Z