Renesas SH7781 - Manual (Page 1241)

24. Multimedia Card Interface (MMCIF)
Rev.1.00 Jan. 10, 2008 Page 1211 of 1658
REJ09B0261-0100
(3) Operation of Commands Not Requiring Command Response
Some broadcast commands do not require a command response.
Figure 24.3 shows an example of the command sequence for commands that do not require a
command response.
Figure 24.4 shows the operational flow for commands that do not require a command response.
• Make settings to issue the command.
• Set the CMDSTART bit in CMDSTRT to 1 to start command transmission. MMCCMD must
be kept driven until the end bit output is completed.
• The end of the command sequence is detected by poling the BUSY flag in CSTR or by the
command transmit end interrupt (CMDI).
MMCCLK
MMCCMD
MMCDAT
CMDSTRT
(CMDSTART)
INTSTR0
(CMDI)
CSTR
(CWRE)
(BUSY)
(REQ)
Input/output pins
Command output (48 bits)
Command transmission
started
Command transmission
ended
Cleared by
software
Command transmission period
Command sequence period
Figure 24.3 Example of Command Sequence for Commands
Not Requiring Command Response