Philips Integrated Circuits PDIUSBH12 - Manual (Page 22)

Philips Semiconductors Product specification
PDIUSBH12 USB 2-port hub
1999 Jul 22 22
CROSSOVER
POINT CROSSOVER
POINT
CROSSOVER
POINT
SV00514
CROSSOVER
POINT
Hub Delay
Downstream
t
HDD
Hub Delay
Upstream
t
HDD
DOWNSTREAM
DIFFERENTIAL
DATA UPSTREAM-
DIFFERENTIAL
DATA
UPSTREAM
DIFFERENTIAL
DATA DOWNSTREAM-
DIFFERENTIAL
DATA
V DD
V
SS
V SS
A. DOWNSTREAM HUB DELAY B. UPSTREAM HUB DELAY
SOP DISTORTION
t
SOP = t HDD (SOP) – t HDD (NEXT J)
LOW SPEED TIMINGS ARE DETERMINED IN THE SAME WAY FOR:
t
LHDD AND t LSOP
Figure 2. Hub Differential Data Delay and SOP distortion
UPSTREAM-
DIFFERENTIAL
DATA
DOWNSTREAM-
DIFFERENTIAL
DATA
V DD
V SS
V SS
A. DOWNSTREAM EOP DELAY B. UPSTREAM EOP DELAY
EOP DELAY
t
EOPD = t EOP–
EOP DELAY RELATIVE TO t HDD
t
EOPDR
= t
EOPD
– t
HDD
EOP SKEW
t
HESK = t EOP+ – t EOP–
LOW SPEED TIMINGS ARE DETERMINED IN THE SAME WAY FOR:
t
LEOPD , t LEOPDR , AND t LHESK
t EOP+ t EOP–
CROSSOVER
POINT
EXTENDED
CROSSOVER
POINT
EXTENDED
UPSTREAM
END OF CABLE
DOWNSTREAM
PORT
t EOP+ t EOP–
CROSSOVER
POINT
EXTENDED
CROSSOVER
POINT
EXTENDED
SV00515
Figure 3. Hub EOP Delay and EOP Skew