USB3250 Standard Microsystems Corporation, USB3250 Datasheet - Page 42

• Manufacturer Part Number: USB3250
• Description: Usb2.0 PHY IC
• Manufacturer: Standard Microsystems Corporation

Revision 1.5 (03-24-06)
8.11
PARAMETER
XCVRSELECT &
TERMSELECT
TIMING
SUSPENDN
T0
T1
T2
T3
T4
TXVALID
DP/DM
In this case, an event internal to the device initiates the resume process. A device with remote wake-
up capability must wait for at least 5ms after the bus is in the idle state before sending the remote
wake-up resume signaling. This allows the hubs to get into their suspend state and prepare for
propagating resume signaling.
The device has 10ms where it can draw a non-suspend current before it must drive resume signaling.
At the beginning of this period the SIE may negate SUSPENDN, allowing the transceiver (and its
oscillator) to power up and stabilize.
Figure 8.7
device that was previously in FS mode would maintain TERMSELECT and XCVRSELECT high.
To generate resume signaling (FS 'K') the device is placed in the "Disable Bit Stuffing and NRZI
encoding" Operational Mode (OPMODE [1:0] = 10), TERMSELECT and XCVRSELECT must be in FS
mode, TXVALID asserted, and all 0's data is presented on the TXDATA bus for at least 1ms (T1 - T2).
Assertion of Resume
time
Internal device event initiating the resume process
Device asserts FS 'K' on the bus to signal resume
request to downstream port
The device releases FS 'K' on the bus. However by
this time the 'K' state is held by downstream port.
Downstream port asserts SE0.
Latest time at which a device, which was previously
in HS mode, must restore HS mode after bus activity
stops.
illustrates the behavior of a device returning to HS mode after being suspended. At T4, a
T0
Figure 8.7 Resume Timing Behavior (HS Mode)
FS Idle ('J')
Table 8.9 Resume Timing Values (HS Mode)
DESCRIPTION
DATASHEET
T1
FS Mode
42
T2
'K' State
0 (reference)
T0 < T1 < T0 + 10ms.
T1 + 1.0ms < T2 < T1 + 15ms
T1 + 20ms
T3 + 1.33µs {2 Low-speed bit
times}
SMSC GT3200, SMSC USB3250
VALUE
T3 T4
SE0
HS Mode
USB2.0 PHY IC
Datasheet