Rainbow Electronics AT89C51SND1C - Manual (Page 115)

115
AT8xC51SND1C
4109E–8051–06/03
Figure 79. MMC Clock Generator and 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 80 shows the MMC controller configura-
tion flow.
As exposed in Section “Clock Control”, page 113, MMCD7:0 bits can be used to dynam-
ically increase or reduce the MMC clock.
Figure 80. Configuration Flow
MMCD7:0
MMCLK
MMC Clock
MMCclk
OSCclk
MMCD 1 +
----------------------------- = OSC
CLOCK
MMCEN
MMCON2.7
Controller Clock
MMC
CLOCK
MMC Clock Symbol
MMC Controller
Configuration
Configure MMC Clock
MMCLK = XXh
MMCEN = 1
FLOWC = 0