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NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 143 -
Revision V1.30
NUC97
0
T
E
CHNIC
A
L
RE
F
E
RE
N
CE
MA
NUA
L
Ethernet MAC Controller Clock Divider
5.3.3.5
RMIIx_REFCLK
(50 MHz)
EMACx_SrcCLK
EMACx_TXCLK
EMACx
(CLK_HCLKEN[x+16])
CLK_SW4
(2-to-1)
(MUX)
OPMOD
(EMACx_MCMDR[20])
÷ 2
÷ 20
x = 0, 1
25 MHz
2.5 MHz
EMACx_RXCLK
Note:
Before clock switching, both the pre-selected and
newly selected clock sources must be turned on and stable.
Figure 5.3-5 Ethernet MAC Controller Clock Divider Block Diagram
GPIO Clock Divider
5.3.3.6
XT1_IN (12 MHz)
GPIO_SrcCLK
ECLK
GPIO
GPIO
(CLK_PCLKEN0[3])
CLK_SW2
(2-to-1)
(MUX)
CLK_DIVn
(÷ (1))
X32_IN (32.768 kHz)
GPIO_S
(CLK_DIVCTL7[7])
GPIO_N
(CLK_DIVCTL7[6:0])
Note:
Before clock switching, both the pre-selected and
newly selected clock sources must be turned on and stable.
Figure 5.3-6 GPIO Clock Divider Block Diagram
I
2
S Controller Clock Divider
5.3.3.7
APLLFout
I
2
S_SDIV
(CLK_DIVCTL1[18:16])
I
2
S_N
(CLK_DIVCTL1[31:24])
I
2
S_SrcCLK
ECLK
I
2
S
I
2
S
(CLK_HCLKEN[24])
ACLKOut
UCLKout
CLK_SW4
(4-to-1)
(MUX)
CLK_DIVn
(÷ (I
2
S_N+1))
UPLLFout
I
2
S_S
(CLK_DIVCTL1[20:19])
XT1_IN
CLK_DIVn
(÷ (I
2
1))
CLK_DIVn
(÷ (I
2
1))
Note:
Before clock switching, both the pre-selected and
newly selected clock sources must be turned on and stable.
Figure 5.3-7 I
2
S Controller Clock Divider Block Diagram