Siemens
Product Manual R0002
Semiconductor Group
26
3.1
least N
RC
clock cycles. This timing is relevant for any host command.
Figure 9: Timing response end to next CMD start (data transfer mode)
After the last command, which does not force a response, has been sent, the host can continue
sending the next command after at least N
CC
clock periods.
Last host command - next host command timing diagram
Figure 10: Timing CMD
n
end to CMD
n+1
start (all modes)
In the case the
CMD
n
command was a last identification command (no more response sent by a
card), then the next
CMD
n+1
command is allowed to follow after at least N
CC
+136 (the length of the
R2 response) clock periods.
Data access timing
Data transmission starts with the access time delay t
AC
(which corresponds to N
AC
), beginning from
the end bit of the data address command. The data transfer stops automatically in case of a data
block transfer or by a transfer stop command.
Figure 11: Data read timing (data transfer mode)
The card data transmission can be stopped using the stop command. The data transmission stops
immediately with the end bit of the stop command.
Data transfer stop command timing
Figure 12: Timing of stop command (CMD12, data transfer mode)
The data transmission stops immediately with the end bit of the host command. The next data block
transmission starts with the access time delay t
AC
, beginning from the end bit of the data address
Data transfer stop - next data block transfer timing
<-------- Response --------> <-N
RC
cycles -> <---- Host command ----->
S T
content
CRC E Z * * * * * * Z S T
CMD
content
CRC E
<----- Host command ----> <-N
CC
cycles -> <---- Host command ----->
S T
content
CRC E Z * * * * * * Z S T
CMD
content
CRC E
<----- Host command -----><-N
CR
cycles -><-------- Response --------->
S T
content
CRC E Z Z P * * * P S T
<-------- N
AC
cycles -------> <- Read Data
Z Z Z
* * * *
Z Z Z Z Z Z P * * * * * * * * * * P S D D D * * *
CMD
content
CRC E
DAT
<----- Host command -----><-N
CR
cycles -><-------- Response --------->
S T
content
CRC E Z Z P * * * P S T
CMD
content
CRC E
DAT
D D D * * * * * * * * D D D E Z Z
* * * * * * * * * * * * * * * * * * * *