CX82100 Home Network Processor Data Sheet
Table 13-3. FCLK PLL Generated Clocks
Clock
Minimum
Frequency
(MHz)
Maximum
Operating
Frequency
(MHz)
Description
FCLK
96
48
168
ARM940T fast clock input, asynchronous to bus clock. Can have a lower minimum if
the USB interface is not used. Internal. FCLK must be equal to or greater than BCLK.
UCLK
84
USB timing reference; always one-half the frequency of FCLK. Must be a multiple of
12 MHz for proper USB operation. Internal. Optionally external, output on FCLKIO
pin.
UDC
12
12
USB timing reference. Must be 12 MHz for proper USB operation; UCLK divided by
number corresponding to PLL_F_CR. Internal.
Table 13-4. BCLK PLL Generated Clocks
Clock
Minimum
Frequency
(MHz)
Maximum
Operating
Frequency
(MHz)
Description
BCLK
PCLK
25
12.5
100
50
ASB clock. Internal. Can have a lower minimum if EPCLK is not used for 25 MHz.
APB clock; always one-half the frequency of BCLK and aligned to BCLK falling edge.
Internal.
EPCLK
25
25
Miscellaneous timing reference, e.g., Ethernet PHY. Optionally external; output on
BCLKIO pin. Can be different frequency for applications other than an Ethernet PHY
clock.
Table 13-5. FCLK PLL Generated Clocks Programming Examples
FCLK Speed Select
(PLL_F_CR_SLOW)
PLL_F
FCLK (ARM)
Frequency
UCLK
USB Clock
Rate Select
(PLL_F_CR)
UDC Clock
Frequency
Notes
Frequency
Frequency
(FCLK/2)
0 (Normal)
0 (Normal)
0 (Normal)
0 (Normal)
1 (Slow)
1 (Slow)
1 (Slow)
1 (Slow)
96 MHz
120 MHz
144 MHz
168 MHz
96 MHz
120 MHz
144 MHz
168 MHz
96 MHz
120 MHz
144 MHz
168 MHz
48 MHz
60 MHz
72 MHz
84 MHz
48 MHz
60 MHz
72 MHz
84 MHz
48 MHz
60 MHz
72 MHz
84 MHz
12 MHz
12 MHz
12 MHz
12 MHz
12 MHz
12 MHz
12 MHz
12 MHz
00 (÷ 8)
01 (÷ 10)
10 (÷ 12)
10 (÷ 14)
00 (÷ 4)
01 (÷ 5)
10 (÷ 6)
10 (÷ 7)
Default at POR
Table 13-6. BCLK PLL Generated Clocks Programming Examples
BCLK Speed Select
(PLL_F_CR_SLOW)
PLL_B
BCLK (ASB)
Frequency
PCLK (APB)
Frequency
(BCLK/2)
EPCLK Clock
Rate Select
(PLL_B_CR)
EPCLK
(XBCLK)
Clock
Notes
Frequency
Frequency
0 (Normal)
0 (Normal)
1 (Slow)
75 MHz
100 MHz
50 MHz
75 MHz
100 MHz
25 MHz
50 MHz
37.5 MHz
50 MHz
12.5MHz
25 MHz
25 MHz
25 MHz
25 MHz
25 MHz
00 (÷ 3)
01 (÷ 4)
00 (÷ 1)
01 (÷ 2)
Default at POR
1 (Slow)
100 MHz
13-4
Conexant Proprietary and Confidential Information
101306C
CONEXANT [ CONEXANT SYSTEMS, INC ]
