ISP1507D1HNUM STEricsson, ISP1507D1HNUM Datasheet - Page 14

• Manufacturer Part Number: ISP1507D1HNUM
• Manufacturer: STEricsson

Specifications of ISP1507D1HNUM

• Lead Free Status / RoHS Status: Compliant

CD00269906
Product data sheet
9.1.2 Low-power mode
Table 4.
[1]
When the USB is idle, the link can place the ISP1507D1 into low-power mode (also called
suspend mode). In low-power mode, the data bus definition changes to that shown in
Table
register (see
signal. The ISP1507D1 will draw only suspend current from the V
Table
During low-power mode, the clock on XTAL1 may be stopped. The clock must be started
again before asserting STP to exit low-power mode. After exiting low-power mode, the
ISP1507D1 will send an RXCMD to the link if a change was detected in any interrupt
source, and the change still exists. An RXCMD may not be sent if the interrupt condition is
removed before exiting.
For more information on low-power mode enter and exit protocols, refer to UTMI+ Low Pin
Interface (ULPI) Specification Rev. 1.1.
Signal
name
DIR
STP
NXT
I = input; O = output; I/O = input/output.
5. To enter low-power mode, the link sets the SUSPENDM bit in the FUNC_CTRL
45).
ULPI signal description
Direction on
ISP1507D1
O
I
O
Section
11.1.2) to logic 0. To exit low-power mode, the link asserts the STP
[1]
Rev. 03 — 28 July 2010
Signal description
Direction: Controls the direction of data bus DATA[7:0]. In
synchronous mode, the ISP1507D1 drives DIR to LOW by default,
making the data bus an input so that the ISP1507D1 can listen for
TXCMDs from the link. The ISP1507D1 drives DIR to HIGH only
when it has data for the link. When DIR and NXT are HIGH, the byte
on the data bus contains decoded USB data. When DIR is HIGH and
NXT is LOW, the byte contains status information called RXCMD
(receive command). The only exception to this rule is when the PHY
returns register read data, where NXT is also LOW, replacing the
usual RXCMD byte. Every change in DIR causes a turnaround cycle
on the data bus, during which DATA[7:0] is not valid and must be
ignored by the link.
DIR is always asserted during low-power and serial modes.
Stop: In synchronous mode, the link drives STP to HIGH for one
cycle after the last byte of data is sent to the ISP1507D1. The link
can optionally assert STP to force DIR to be deasserted.
In low-power and serial modes, the link holds STP at HIGH to wake
up the ISP1507D1, causing the ULPI bus to return to synchronous
mode.
Next: In synchronous mode, the ISP1507D1 drives NXT to HIGH to
throttle data. If DIR is LOW, the ISP1507D1 asserts NXT to notify the
link to place the next data byte on DATA[7:0] in the following clock
cycle. If DIR is HIGH, the ISP1507D1 asserts NXT to notify the link
that a valid USB data byte is on DATA[7:0] in the current cycle. The
ISP1507D1 always drives an RXCMD when DIR is HIGH and NXT is
LOW, unless register read data is to be returned to the link in the
current cycle.
NXT is not used in low-power or serial mode.
…continued
ULPI HS USB host and peripheral transceiver
CC
ISP1507D1
© ST-ERICSSON 2010. All rights reserved.
supply (see
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