USB 2.0 Hi-Speed Hub Controller
Datasheet
8.6.1.1
RESET_N for Strapping Option Configuration
Hardware
reset
asserted
Drive Strap
Outputs to
inactive
levels
Attach
USB
Upstream
Start
completion
request
response
Read Strap
Options
USB Reset
recovery
Idle
t1
t2
RESET_N
t5
t3
t6
t7
t8
VSS
t4
Strap Pins
Don’t Care
VSS
Valid
Don’t Care
Driven by Hub if strap is an output.
Figure 8.3 Reset_N Timing for Default/Strap Option Mode
Table 8.7 Reset_N Timing for Default/Strap Option Mode
NAME
t1
t2
t3
t4
t5
t6
t7
t8
DESCRIPTION
RESET_N Asserted.
Strap Setup Time
Strap Hold Time.
hub outputs driven to inactive logic states
USB Attach (See Note).
Host acknowledges attach and signals USB
Reset.
USB Idle.
Completion time for requests (with or without data
stage).
Notes:
When in bus-powered mode, the hub and its associated circuitry must not consume more than 100
mA from the upstream USB power source during t1+t5.
All power supplies must have reached the operating levels mandated in
prior to (or coincident with) the assertion of RESET_N.
100
undefined
5
MIN
1
16.7
16.7
1.5
1400
2
100
TYP
MAX
UNITS
μsec
nsec
nsec
μsec
msec
msec
msec
msec
Revision 1.0 (3-11-09)
56
SMSC USB251x
DATASHEET
SMSC [ SMSC CORPORATION ]
