USB3500 Datasheet, PDF (33/45 Pages) SMSC Corporation – Hi-Speed USB Host, Device or OTG PHY With UTMI+ Interface

USB3500
FIGURE 6-6:
HS DETECTION HANDSHAKE TIMING BEHAVIOR FROM SUSPEND
T0
time
OPMODE 0
OPMODE 1
XCVRSELECT
T1 T2
T3 T4
TERMSELECT
SUSPENDN
TXVALID
CLK60
DP/DM
J
SE0
CLK power up time
Device Chirp K
Look for host chirps
To detect the assertion of the downstream Chirp K's and Chirp J's for 2.5us {T_FILT}, the Link must see the appropriate
LINESTATE signals asserted continuously for 165 CLKOUT cycles.
TABLE 6-9: HS DETECTION HANDSHAKE TIMING VALUES FROM SUSPEND
Timing Parameter
Description
Value
T0
While in suspend state an SE0 is detected on the USB. HS 0 (HS Reset T0)
Handshake begins. D+ pull-up enabled, HS terminations
disabled, SUSPENDN negated.
T1
First transition of CLKOUT. CLKOUT “Usable” (frequency
T0 < T1 < T0 + 5.6ms
accurate to ±10%, duty cycle accurate to 50±5).
T2
Device asserts Chirp K on the bus.
T1 < T2 < T0 + 5.8ms
T3
Device removes Chirp K from the bus. (1 ms minimum width) T2 + 1.0 ms < T3 <
and begins looking for host chirps.
T0 + 7.0 ms
T4
CLK “Nominal” (CLKOUT is frequency accurate to ±500 ppm, T1 < T3 < T0 + 20.0ms
duty cycle accurate to 50±5).
6.11 Assertion of Resume
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 Link may negate SUSPENDN, allowing the transceiver (and its oscillator) to power up and stabilize.
Figure 6-7 illustrates the behavior of a device returning to HS mode after being suspended. At T4, a device that was
previously in FS mode would maintain TERMSELECT and XCVRSELECT high.
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DS00002103A-page 33