USB2513 Datasheet, PDF (40/48 Pages) SMSC Corporation – USB 2.0 High-Speed 3-Port Hub Controller

USB 2.0 High-Speed 3-Port Hub Controller
Datasheet
4.7.2.3 RESET_N for SMBus Slave Configuration
Hardware
Reset
SMBus Code Hub PHY
Attach _{USB Reset}
Start
completion
reset
asserted
Negation
Load
Stabilization
USB
Upstream
recovery
Idle
request
response
RESET_N
t1
t2
t3
t4
t5
t6
t7
VSS
Figure 4.6 Reset_N Timing for SMBus Mode
Table 4.7 Reset_N Timing for SMBus Mode
NAME
DESCRIPTION
MIN
TYP
t1
RESET_N Asserted.
1
t2
Hub Recovery/Stabilization.
t3
SMBus Code Load (See Note).
250
t4
Hub Configuration and USB Attach.
t5
Host acknowledges attach and signals USB
100
Reset.
t6
USB Idle.
Undefined
t7
Completion time for requests (with or without data
stage).
MAX
500
300
100
5
UNITS
μsec
μsec
msec
msec
msec
msec
msec
4.7.3
Notes:
„ For Bus-Powered configurations, the 99.5ms (MAX) is required, and the Hub and its associated
circuitry must not consume more than 100mA from the upstream USB power source during
t2+t3+t4+t5+t6+t7. For Self-Powered configurations, t3 MAX is not applicable and the time to load
the configuration is determined by the external SMBus host.
„ All Power Supplies must have reached the operating levels mandated in Chapter 5, DC
Parameters, prior to (or coincident with) the assertion of RESET_N.
USB Bus Reset
In response to the upstream port signaling a reset to the Hub, the Hub does the following:
Note: The Hub does not propagate the upstream USB reset to downstream devices.
1. Sets default address to 0.
2. Sets configuration to: Unconfigured.
3. Negates PRTPWR[3:1] to all downstream ports.
4. Clears all TT buffers.
Revision 1.98 (11-19-07)
40
DATASHEET
SMSC USB2513