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© 2009 Advanced Micro Devices, Inc.
45732 AMD 780E Databook 3.10
Proprietary
4-1
Chapter 4
Timing Specifications
4.1
HyperTransport
TM
Bus Timing
For HyperTransport bus timing information, please refer to CPU specifications.
4.2
HyperTransport
TM
Reference Clock Timing Parameters
Table 4-1 Timing Requirements for HyperTransport Reference Clock (100MHz) Output by the Clock Generator
Symbol
Parameter
Minimum
Maximum
Unit
Note
V
CROSS
Change in Crossing point voltage over all edges
-
140
mV
1
F
Frequency
99.9
100
MHz
2
ppm
Long Term Accuracy
-300
+300
Ppm
3
S
FALL
Output falling edge slew rate
-10
-0.5
V/ns
4, 5
S
RISE
Output rising edge slew rate
0.5
10
V/ns
4, 5
T
jc max
Jitter, cycle to cycle
-
150
ps
6
T
j-accumulated
Accumulated jitter over a 10
s period
-1
1
ns
7
V
D(PK-PK)
Peak to Peak Differential Voltage
400
2400
mV
8
V
D
Differential Voltage
200
1200
mV
9
V
D
Change in V
DDC
cycle to cycle
-75
75
mV
10
DC
Duty Cycle
45
55
%
11
Notes:
More details are available in
AMD HyperTransport 3.0 Reference Clock Specification
and
AMD Family 10h Processor Reference Clock
Parameters
, order # 34864.
1 Single-ended measurement at crossing point. Value is maximum-minimum over all time. DC value of common mode is not important
due to blocking cap.
2 Minimum frequency is a consequence of 0.5% down spread spectrum.
3 Measured with spread spectrum turned off.
4 Only simulated at the receive die pad. This parameter is intended to give guidance for simulation. It cannot be tested on a tester but
is guaranteed by design.
5 Differential measurement through the range of ±100mV, differential signal must remain monotonic and within slew rate specification
when crossing through this region.
6 T
jc
max
is the maximum difference of t
CYCLE
between any two adjacent cycles.
7 Accumulated T
jc
over a 10
s time period, measured with JIT2 TIE at 50ps interval.
8 V
D(PK-PK)
is the overall magnitude of the differential signal.
9 V
D(min)
is the amplitude of the ring-back differential measurement, guaranteed by design that the ring-back will not cross 0V V
D
.
V
D(max)
is the largest amplitude allowed.
10 The difference in magnitude of two adjacent V
DDC
measurements. V
DDC
is the stable post overshoot and ring-back part of the
signal.
11 Defined as t
HIGH
/t
CYCLE
.