SYS_SEL_48M
reg01 |= SYS_SEL_48M;
reg01 |= SYS_SEL_48M | V_TX_EN;
reg01 &= ~SYS_SEL_48M; /* 640x480: clk 24Mhz */
reg01 &= ~SYS_SEL_48M; /* clk 24Mz */
reg01 &= ~SYS_SEL_48M; /* clk 24Mz */
reg01 &= ~SYS_SEL_48M; /* clock 24MHz */