USB2504-JD Standard Microsystems Corp., USB2504-JD Datasheet - Page 36

• Manufacturer Part Number: USB2504-JD
• Description: Interface, Integrated USB2.0 Compatible 4-Port Hub
• Manufacturer: Standard Microsystems Corp.

Revision 1.3 (06-28-04)
5.6.1.3
5.6.2
NAME
RESET_N
t1
t2
t3
t4
t5
t6
t7
VSS
Hardware
asserted
reset
RESET_N Asserted.
Hub Recovery/Stabilization.
SMBus Code Load (See Note).
Hub Configuration and USB Attach.
Host acknowledges attach and signals USB
Reset.
USB Idle.
Completion time for requests (with or without data
stage).
RESET_N for SMBus Slave Configuration
Note: For Bus-Powered configurations, the 99.5ms (MAX) is required, and the Hub and its associated
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[4:1] to all downstream ports.
4. Clears all TT buffers.
5. Moves device from suspended to active (if suspended).
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.
t1
Negation
Reset
DESCRIPTION
Figure 5.4 Reset_N Timing for SMBus Mode
Table 5.7 Reset_N Timing for SMBus Mode
SMBus Code
t2
Load
Stabilization
t3
Hub PHY
30
t4
Upstream
Attach
USB
MIN
100
100
USB Reset
recovery
t5
Undefined
Integrated USB2.0 Compatible 4-Port Hub
TYP
10
t6
Idle
MAX
99.5
500
100
5
t7
completion
response
request
SMSC USB2504
Start
UNITS
Datasheet
msec
msec
msec
msec
msec
nsec
µsec