AT8xC51SND2C
Figure 91. MMC Clock Generator and Symbol
OSCclk
MMCD + 1
OSC
CLOCK
MMCclk = ----------------------------
Controller Clock
MMC Clock
MMCLK
MMC
CLOCK
MMCEN
MMCON2.7
MMCD7:0
MMC Clock Symbol
As soon as MMCEN bit in MMCON2 is set, the MMC controller receives its system
clock. The MMC command and data clock is generated on MCLK output and sent to the
command line and data line controllers. Figure 92 shows the MMC controller configura-
tion flow.
As exposed in Section “Clock Control”, page 139, MMCD7:0 bits can be used to dynam-
ically increase or reduce the MMC clock.
Figure 92. Configuration Flow
MMC Controller
Configuration
Configure MMC Clock
MMCLK = XXh
MMCEN = 1
FLOWC = 0
141
4341D–MP3–04/05
ATMEL [ ATMEL ]
