Rainbow Electronics W90N740 User Manual
Page 37
W90N740
Publication Release Date: November 26, 2004
- 33 -
Revision A4
Clock Select Register (CLKSEL)
REGISTER ADDRESS
R/W
DESCRIPTION
RESET
VALUE
CLKSEL 0xFFF0.000C R/W Clock Select Register
0x0000.3FX8
31
30
29
28
27
26
25
24
RESERVED
23
22
21
20
19
18
17
16
RESERVED
15
14
13
12
11
10
9
8
USBCKS RESERVED GDMA
NATA
EMC1
EMC0
WDTS
WDT
7
6
5
4
3
2
1
0
USB TIMER UART ECLKS
CLKS
RESET
USBCKS [15] ： USB clock source Select bit
0 = USB clock 48MHz input from internal PLL ( 480MHz/10)
1 = USB clock 48MHz input from external GP12 pin, this GPIO pin direction must set to input.
GDMA [13] ： GDMA clock enable bit
0 = Disable GDMA clock
1 = Enable GDMA clock
NATA [12] ： NATA clock enable bit
0 = Disable NATA clock
1 = Enable NATA clock
EMC1 [11] ： EMC1 clock enable bit
0 = Disable EMC1 clock
1 = Enable EMC1 clock
EMC0 [10] ： EMC0 clock enable bit
0 = Disable EMC0 clock
1 = Enable EMC0 clock
WDTS [9] : WDTS clock selected bit
0 = Clock from EXTAL pin is used as WDT counting clock
1 = Clock from EXTAL pin is divided by 256, which is used as WDT counting clock