Samsung S5PC100, User Manual, Page: 983 / 1863

SD/MMC CONTROLLER S5PC100 USER’S MANUAL (REV1.0)
8.12-48
CLKCON Bit Description Reset Value
Reserved [7:4] Reserved
STBLEXTCLK [3]
External Clock Stable
This bit is set to 1 if SD Clock output is stable after writing to SD Clock
Enable in this register to 1. The SD Host Driver waits to issue command
to start until this bit is set to 1. (ROC)
‘1’ = Ready
‘0’ = Not Ready
0
ENSDCLK [2] SD Clock Enable
The Host Controller stops SDCLK if this bit is written to 0. SDCLK
Frequency Select changes if this bit is 0. Then, the Host Controller
maintains the same clock frequency until
SDCLK is stopped (Stop at
SDCLK =0). If the Card Inserted in the Present State register is cleared,
this clears the bit (RW).
'1' = Enables
'0' = Disables
0
STBLINTCLK [1] Internal Clock Stable
This bit is set to 1 if SD Clock is stable after writing to Internal Clock
Enable in this register to 1. The SD Host Driver waits to set SD Clock
Enable until this bit is set to 1.
Note: This is useful if PLL is used for a clock oscillator that requires
setup time. (ROC)
'1' = Ready
'0' = Not Ready
0
ENINTCLK [0] Internal Clock Enable
This bit is set to 0 if the Host Driver is not using the Host Controller or
the Host Controller awaits a wakeup interrupt. The Host Controller must
stop its internal clock to go at very low power state. Still, registers is able
to be read and written. Clock starts to oscillate when this bit is set to 1. If
clock oscillation is stable, the Host Controller can be set Internal Clock
Stable in this register to 1. This bit does not affect card detection. (RW)
'1' = Oscillate
'0' = Stop