USB2640I Standard Microsystems Corp., USB2640I Datasheet - Page 49

• Manufacturer Part Number: USB2640I
• Description: Industrial Temperature Usb 2.0 Flash Media Controller And Usb Hub Combo
• Manufacturer: Standard Microsystems Corp.

Industrial Temperature USB 2.0 Flash Media Controller and USB Hub Combo
SMSC USB2640i/USB2641i
7.5.2.1
7.5.3
NAME
t1
t2
t3
t4
t5
t6
t7
RESET_N
RESET_N asserted.
Device recovery/stabilization.
8051 programs device configuration
USB attach (See Note).
Host acknowledges attach and signals USB reset.
USB idle.
Completion time for requests (with or without data
stage).
VSS
RESET_N for EEPROM Configuration
Note: All power supplies must have reached the operating levels mandated in
USB Bus Reset
In response to the upstream port signaling a reset to the device, the device does the following:
Note: The device does not propagate the upstream USB reset to downstream devices.
1. Sets default address to 0.
2. Sets configuration to: Unconfigured.
3. Negates PRTCTL[3:2] to all downstream ports.
4. Clears all TT buffers.
5. Moves device from suspended to active (if suspended).
6. Complies with Section 11.10 of the USB 2.0 Specification for behavior after completion of the reset
The host then configures the device and the device’s downstream port devices in accordance with the
USB Specification.
Hardware
asserted
sequence.
reset
Parameters, prior to (or coincident with) the assertion of RESET_N.
Stabilization
Recovery/
t1
DESCRIPTION
Device
Figure 7.1 Reset_N Timing for EEPROM Mode
Table 7.7 Reset_N Timing for EEPROM Mode
Configuration
t2
8051 Sets
Registers
DATASHEET
t4
49
t3
Upstream
Attach
USB
MIN
100
1
USB Reset
recovery
t5
Undefined
TYP
20
t6
Idle
MAX
500
100
50
Revision 2.0 (10-03-08)
5
t7
completion
Chapter 9, DC
response
request
Start
UNITS
msec
msec
msec
msec
msec
μsec
μsec