SAM3S8B Atmel Corporation, SAM3S8B Datasheet - Page 830

• Manufacturer Part Number: SAM3S8B
• Manufacturer: Atmel Corporation

830
830
SAM3S8/SD8
SAM3S8/SD8
The two bus modes (open drain and push/pull) needed to process all the operations are defined
in the HSMCI command register. The HSMCI_CMDR allows a command to be carried out.
For example, to perform an ALL_SEND_CID command:
The command ALL_SEND_CID and the fields and values for the HSMCI_CMDR Control Regis-
ter are described in
Table 34-6.
Note:
Table 34-7.
The HSMCI_ARGR contains the argument field of the command.
To send a command, the user must perform the following steps:
The command is sent immediately after writing the command register.
While the card maintains a busy indication (at the end of a STOP_TRANSMISSION command
CMD12, for example), a new command shall not be sent. The NOTBUSY flag in the status regis-
ter (HSMCI_SR) is asserted when the card releases the busy indication.
If the command requires a response, it can be read in the HSMCI response register
(HSMCI_RSPR). The response size can be from 48 bits up to 136 bits depending on the com-
mand. The HSMCI embeds an error detection to prevent any corrupted data during the transfer.
CMD
CMD Index
CMD2
Field
CMDNB (command number)
RSPTYP (response type)
SPCMD (special command)
OPCMD (open drain command)
MAXLAT (max latency for command to response)
TRCMD (transfer command)
TRDIR (transfer direction)
TRTYP (transfer type)
IOSPCMD (SDIO special command)
• Fill the argument register (HSMCI_ARGR) with the command argument.
• Set the command register (HSMCI_CMDR) (see
1. bcr means broadcast command with response.
S
T
ALL_SEND_CID Command Description
Fields and Values for HSMCI_CMDR Command Register
Type
bcr
Host Command
Content
(1)
Table 34-6
Argument
[31:0] stuff bits
CRC
and
Table
E
Z
34-7.
N
Resp
R2
ID
******
Cycles
Value
2 (CMD2)
2 (R2: 136 bits response)
0 (not a special command)
1
0 (NID cycles ==> 5 cycles)
0 (No transfer)
X (available only in transfer command)
X (available only in transfer command)
0 (not a special command)
Table
Abbreviation
ALL_SEND_CID
Z
S
34-7).
T
Content
CID
Command
Description
Asks all cards to send
their CID numbers on
the CMD line
11090A–ATARM–10-Feb-12
11090A–ATARM–10-Feb-12
Z
Z
Z