Renesas SH7781 User Manual

Page 1241

24. Multimedia Card Interface (MMCIF)

Rev.1.00 Jan. 10, 2008 Page 1211 of 1658

REJ09B0261-0100

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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