Clocking
Copyright © 2008 Marvell
Doc. No. MV-S104859-U0 Rev. E
December 2, 2008, Preliminary
Document Classification: Proprietary Information
Page 61
The following table lists the supported combinations of the CPU_CLK Frequency select, CPU_CLK
to DDR CLK ratio, and to CPU_CLK to CPU L2 clock ratio (see
Section 6.5, Pins Sample
Configuration, on page 66
).
SATA PHY PLL
•
Reference clock:
REF_CLK_XIN (25 MHz)
•
Derivative clock:
SATA Clock (150 MHz)
RTC
•
Reference clock:
RTC_XIN (32.768 kHz)
Used for real time clock functionality, see the Real Time Clock section in the
88F6180, 88F6190, 88F6192, and 88F6281 Functional Specifications.
PTP
•
Reference clock:
PTP_CLK (125 MHz)
The PTP_CLK can be used for the following functions:
•
PTP time stamp clock
Two options for reference clock:
- PTP_CLK
- Gigabit Ethernet Clock (125 MHz)
•
TS unit clock
Two options for reference clock:
- PTP_CLK/2
- Core PLL
•
Audio unit clock
Two options for reference clock:
- PTP_CLK
- REF_CLK_XIN (25 MHz)
For clocking configuration registers, see the 88F6180, 88F6190, 88F6192, and
88F6281 Functional Specifications.
Table 30: Supported Clock Combinations
D D R C l o c k
( M H z )
C P U t o D D R
C l o c k R a t i o
C P U C l o c k
( M H z )
C P U t o L 2
C l o c k R a t i o
L 2 C l o c k
( M H z )
333
250
200
3:1
4:1
5:1
1000
3:1
333
400
300
267
200
3:1
4:1
4.5:1
6:1
1200
3:1
400
375
4:1
1500
3:1
500
Table 29: 88F6281Clocks (Continued)
C l o c k Ty p e
D e s c r i p t i o n
Summary of Contents for Integrated Controller 88F6281
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