Datasheet

587
SAM9G15 [DATASHEET]
11052D–ATARM–31-Oct-12
The following flowchart shows how to send a command to the card and read the response if needed. In this example, the
status register bits are polled but setting the appropriate bits in the Interrupt Enable Register (HSMCI_IER) allows using
an interrupt method.
Figure 34-7. Command/Response Functional Flow Diagram
Note: 1. If the command is SEND_OP_COND, the CRC error flag is always present (refer to R3 response in the High Speed
MultiMedia Card specification).
RETURN OK
RETURN ERROR
(1)
RETURN OK
Set the command argument
HSMCI_ARGR = Argument
(1)
Set the command
HSMCI_CMDR = Command
Read HSMCI_SR
CMDRDY
Status error flags?
Read response if required
Ye s
Wait for command
ready status flag
Check error bits in the
status register
(1)
0
1
Does the command involve
a busy indication?
No
Read HSMCI_SR
0
NOTBUSY
1