USB 2.0 Hi-Speed Hub Controller
Datasheet
8.6.1.2
RESET_N for EEPROM Configuration
Hardware
reset
asserted
Read EEPROM
+
Set Options
Attach
USB
Upstream
Start
completion
request
response
Read Strap
Options
USB Reset
recovery
Idle
t4
t1
RESET_N
t2
t3
t5
t6
t7
VSS
Figure 8.4 Reset_N Timing for EEPROM Mode
Table 8.8 Reset_N Timing for EEPROM Mode
NAME
t1
t2
t3
t4
t5
t6
t7
DESCRIPTION
RESET_N Asserted.
Hub Recovery/Stabilization.
EEPROM Read / Hub Config.
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 t4+t5+t6+t7.
All power supplies must have reached the operating levels mandated in
prior to (or coincident with) the assertion of RESET_N.
100
undefined
5
2.0
MIN
1
500
99.5
100
TYP
MAX
UNITS
μsec
μsec
msec
msec
msec
msec
msec
SMSC USB251x
57
Revision 1.0 (3-11-09)
DATASHEET
SMSC [ SMSC CORPORATION ]
