ISP1705AETTM STEricsson, ISP1705AETTM Datasheet - Page 43

• Manufacturer Part Number: ISP1705AETTM
• Manufacturer: STEricsson

Specifications of ISP1705AETTM

• Lead Free Status / RoHS Status: Compliant

ISP1705_2
Product data sheet
10.8.1 Full-speed or low-speed host-initiated suspend and resume
10.8 USB suspend and resume
Figure 20
suspend and sometime later initiates resume signaling to wake-up the downstream
peripheral. Note that
LINESTATE updates.
The sequence of events for a host and a peripheral, both with ISP1705, is as follows:
1. Idle: Initially, the host and the peripheral are idle. The host has its 15 k
2. Suspend: When the peripheral sees no bus activity for 3 ms, it enters the suspend
3. Resume K: When the host wants to wake up the peripheral, it sets OPMODE[1:0] to
4. EOP: When STP is asserted, the ISP1705 on the host side automatically appends an
Fig 19. Preamble sequence
DATA[7:0]
resistors enabled (DP_PULLDOWN and DM_PULLDOWN are set to 1b) and 45
terminations are disabled (TERMSELECT is set to 1b). The peripheral has the 1.5 k
pull-up resistor connected to DP for full speed or DM for low speed (TERMSELECT is
set to 1b).
state. The peripheral link places the PHY into low-power mode by clearing the
SUSPENDM bit in the FUNC_CTRL register (see
draw only suspend current. The host may or may not be powered down.
10b and transmits a K for at least 20 ms. The peripheral link sees the resume K on
LINESTATE, and asserts STP to wake up the PHY.
EOP of two bits of SE0 at low-speed bit rate, followed by one bit of J. The ISP1705 on
the host side knows to add the EOP because DP_PULLDOWN and DM_PULLDOWN
are set to 1b for a host. After the EOP is completed, the host link sets OPMODE[1:0]
to 00b for normal operation. The peripheral link sees the EOP and also resumes
normal operation.
DP or DM
CLOCK
NXT
STP
DIR
DP and DM timing is not to scale.
illustrates how a host or a hub places a full-speed or low-speed peripheral into
Figure 20
Rev. 02 — 21 January 2009
FS SYNC
TXCMD (low-speed packet ID)
timing is not to scale, and does not show all RXCMD
PRE ID
FS
IDLE (min
4 FS bits)
LS SYNC
Section
ULPI Hi-Speed USB transceiver
D0
LS PID
11.5), causing the PHY to
D1
LS D0
© ST-NXP Wireless 2009. All rights reserved.
ISP1705
LS D1
pull-down
004aaa714
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