USB2660 Standard Microsystems Corp., USB2660 Datasheet - Page 54

• Manufacturer Part Number: USB2660
• Description: Ultra Fast Usb 2.0 Hub And Multi-format Flash Media Controller With Dual Sd Interfaces
• Manufacturer: Standard Microsystems Corp.

Revision 1.0 (06-09-09)
8.5
8.6
8.6.1
8.6.2
8.6.2.1
NAME
t1
t2
nRESET
nRESET asserted
Device recovery/stabilization
VSS
The SMSC device can be configured via its internal default configuration. Please see
"EEPROM Data Descriptor"
Table 8.1
There are three different resets that the device experiences. One is a hardware reset from the internal
power-on reset (POR) circuit, another reset is via the nRESET pin, and the third is a USB bus reset.
Internal POR Hardware Reset
All reset timing parameters are guaranteed by design.
External Hardware nRESET
A valid hardware reset is defined as assertion of nRESET for a minimum of 1 μs after all power
supplies are within operating range. While reset is asserted, the device (and its associated external
circuitry) consumes less than 500 μA of current from the upstream USB power source.
Assertion of nRESET (external pin) causes the following:
1. All downstream ports are disabled and PRTCTL power to downstream devices is removed.
2. The PHYs are disabled and the differential pairs will be in a high-impedance state.
3. All transactions immediately terminate; no states are saved.
4. All internal registers return to the default state (in most cases, 00h).
5. The external crystal oscillator is halted.
6. The PLL is halted.
nRESET for EEPROM Configuration
Default Configuration Option
Reset
Hardware
asserted
reset
for the internal default values that are loaded when this option is selected.
Stabilization
Recovery/
t1
DESCRIPTION
Device
Figure 8.1 nRESET Timing for EEPROM Mode
Table 8.7 nRESET Timing for EEPROM Mode
Ultra Fast USB 2.0 Hub and Multi-Format Flash Media Controller with Dual SD Interfaces
Configuration
for specific details on how to enable default configuration. Please refer to
t2
8051 Sets
Registers
DATASHEET
t4
54
t3
Upstream
Attach
USB
MIN
1
USB Reset
recovery
t5
TYP
t6
Idle
SMSC USB2660/USB2660i
MAX
500
t7
completion
response
request
Section 8.3.2,
Start
UNITS
Datasheet
μsec
μsec