March 1997
ML6510*
Series Programmable Adaptive
Clock Manager (PACMan™)
GENERAL DESCRIPTION
The ML6510 (Super PACMan™) is a Programmable
Adaptive Clock Manager which offers an ideal solution for
managing high speed synchronous clock distribution in
next generation, high speed personal computer and
workstation system designs. It provides eight channels of
deskew buffers that adaptively compensate for clock skew
using only a single trace. The input clock can be either
TTL or PECL, selected by a bit in the control register.
Frequency multiplication or division is possible using the
M&N divider ratio, within the maximum frequency limit.
0.5X, 1X, 2X and 4X clocks can be easily realized.
The ML6510 is implemented using a low jitter PLL with
on-chip loop filter. The ML6510 deskew buffers adaptively
compensate for clock skew on PC boards. An internal
skew sense circuit is used to sense the skew caused by the
PCB trace and load delays. The sensing is done by
detecting a reflection from the load and the skew is
corrected adaptively via a unique phase control delay
circuit to provide low load-to-load skew, at the end of the
PCB traces. Additionally, the ML6510 supports PECL
reference clock outputs for use in the generation of clock
trees with minimal part-to-part skew. The chip configuration
can be programmed to generate the desired output
frequency using the internal ROM or an external serial
EEPROM or a standard two-wire serial microprocessor
interface.
FEATURES
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Input clocks can be either TTL or PECL with low
input to output clock phase error
8 independent, automatically deskewed clock
outputs with up to 5ns of on-board deskew range
(10ns round trip)
Controlled edge rate TTL-compatible CMOS clock
outputs capable of driving 40Ω PCB traces
10 to 80MHz (6510-80) or 10 to 130MHz (6510-130)
input and output clock frequency range
Less than 500ps skew between inputs
at the
device loads
Small-swing reference clock outputs for minimizing
part-to-part skew
Frequency multiplication or division is possible using
the M&N divider ratio
Lock output indicates PLL and deskew buffer lock
Test mode operation allows PLL and deskew buffer
bypass for board debug
Supports industry standard processors like Pentium,
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Mips, SPARC, PowerPC, Alpha, etc.
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*Some Packages Are Obsolete
SYSTEM BLOCK DIAGRAM
LOCAL BUS
CPU
CACHE
CONTROLLER
CACHE
RAM
CLK
CLOCK SUBSYSTEM
CLOCK IN
ML6510
•
8 •
•
CLOCK OUT TO
COMPONENTS
MEMORY BUS
MEMORY BUS
CONTROLLER
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MICRO-LINEAR [ MICRO LINEAR CORPORATION ]
