USB 2.0 Hi-Speed Hub Controller
Datasheet
8.6.1.2
RESET_N for EEPROM Configuration
Start
completion
request
Hardware
reset
asserted
Read EEPROM
+
Set Options
Attach
USB
Upstream
Read Strap
Options
USB Reset
recovery
Idle
response
t4
t6
t7
t1
t5
t2
t3
RESET_N
VSS
Figure 8.4 Reset_N Timing for EEPROM Mode
Table 8.8 Reset_N Timing for EEPROM Mode
NAME
DESCRIPTION
MIN
TYP
MAX
UNITS
t1
t2
t3
t4
t5
RESET_N Asserted.
1
μsec
μsec
msec
msec
msec
Hub Recovery/Stabilization.
EEPROM Read / Hub Config.
USB Attach (See Note).
500
99.5
100
2.0
Host acknowledges attach and signals USB
Reset.
100
t6
t7
USB Idle.
undefined
msec
msec
Completion time for requests (with or without data
stage).
5
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 Chapter 9, DC Parameters,
prior to (or coincident with) the assertion of RESET_N.
SMSC USB251x
57
Revision 1.0 (3-11-09)
DATASHEET
SMSC [ SMSC CORPORATION ]
