ISP1705AETTM STEricsson, ISP1705AETTM Datasheet - Page 32

• Manufacturer Part Number: ISP1705AETTM
• Manufacturer: STEricsson

Specifications of ISP1705AETTM

• Lead Free Status / RoHS Status: Compliant

10. Protocol description
ISP1705_2
Product data sheet
10.1 ULPI references
10.2 TXCMD
10.3 RXCMD
The ISP1705 provides a 12-pin ULPI interface to communicate with the link. It is highly
recommended that users of the ISP1705 read UTMI+ Specification Rev. 1.0 and UTMI+
Low Pin Interface (ULPI) Specification Rev. 1.1.
Commands between the ISP1705 and the link are described in the following subsections.
By default, the link must drive the ULPI bus to its idle state of 00h. To send commands and
USB packets, the link drives a nonzero value on DATA[7:0] to the ISP1705 by sending a
byte called TXCMD. Commands include USB packet transmissions, and register reads
and writes. Once the TXCMD is interpreted and accepted by the ISP1705, the NXT signal
is asserted and the link can follow up with the required number of data bytes. The TXCMD
byte format is given in
will result in undefined behavior.
Various TXCMD packet and register sequences are given in later sections.
Table 16.
The ISP1705 communicates status information to the link by asserting DIR and sending
an RXCMD byte on the data bus. The RXCMD data byte format follows UTMI+ Low Pin
Interface (ULPI) Specification Rev. 1.1 and is given in
Command
type name
Idle
Packet
transmit
Register
write
Register
read
TXCMD byte format
Command
code
DATA[7:6]
00b
01b
10b
11b
Rev. 02 — 21 January 2009
Table
Command
payload
DATA[5:0]
00 0000b
00 0000b
00 XXXXb
10 1111b
XX XXXXb
10 1111b
XX XXXXb
16. Any values other than those in
Command
name
NOOP
NOPID
PID
EXTW
REGW
EXTR
REGR
Command description
No operation. 00h is the idle value of the
data bus. The link must drive NOOP by
default.
Transmit USB data that does not have a
PID, such as chirp and resume signaling.
The ISP1705 starts transmitting only after
accepting the next data byte.
Transmit USB packet. DATA[3:0]
indicates USB packet identifier PID[3:0].
Extended register write command
(optional). The 8-bit address must be
provided after the command is accepted.
Register write command with 6-bit
immediate address.
Extended register read command
(optional). The 8-bit address must be
provided after the command is accepted.
Register read command with 6-bit
immediate address.
Table
ULPI Hi-Speed USB transceiver
17.
Table 16
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ISP1705
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