GD32W51x User Manual
769
CMD40 is mandatory for SDHC. The other classes are optional. The supported Card
Command Classes (CCC) are coded as a parameter in the card specific data (CSD) register
of each card, providing the host with information on how to access the card.
For MMC cards, Class 0 is mandatory and shall be supported. The other classes are either
mandatory only for specific card types or optional. By using different classes, several
configurations can be chosen (e.g. a block writable card or a stream readable card). The
supported Card Command Classes (CCC) are coded as a parameter in the card specific data
(CSD) register of each card, providing the host with information on how to access the card.
For CE-ATA device, the device shall support the MMC commands required to achieve the
transfer state during device initialization. Other interface configuration settings, such as bus
width, may require additional MMC commands also be supported. See the MMC reference.
CE-ATA makes use of the following MMC commands: CMD0 - GO_IDLE_STATE, CMD12 -
STOP_TRANSMISSION, CMD39 - FAST_IO, CMD60 - RW_MULTIPLE_REGISTER,
CMD61 - RW_MULTIPLE_BLOCK. GO_IDLE_STATE (CMD0), STOP_TRANSMISSION
(CMD12), and FAST_IO (CMD39) are as defined in the MMC reference.
RW_MULTIPLE_REGISTER (CMD60) and RW_MULTIPLE_BLOCK (CMD61) are MMC
commands defined by CE-ATA.
Table 23-3. Card command classes (CCCs)
Card
com m and
class(CCC)
0
1
2
3
4
5
6
7
8
9
10
11
Supported
com m and
Class
description
b
a
s
ic
S
tr
e
a
m
r
e
a
d
B
lo
c
k
r
e
a
d
S
tr
e
a
m
w
ri
te
B
lo
c
k
w
ri
te
e
ra
s
e
w
ri
te
p
ro
te
c
ti
o
n
L
o
c
k
c
a
rd
a
p
p
li
c
a
ti
o
n
s
p
e
c
if
ic
I/
O
m
o
d
e
s
w
it
c
h
re
s
e
rv
e
d
CMD0
M
+
CMD1
M
+
CMD2
M
+
CMD3
M
+
CMD4
M
+
CMD5
O
+
CMD6
M
+
CMD7
M
+
CMD8
M
+
CMD9
M
+
CMD10
M
+
CMD11
M
+
CMD12
M
+
CMD13
M
+