Philips ISP1122A Operation manual

ISP1122A
Universal Serial Bus stand-alone hub
Rev. 03 — 30 October 2001 Product data
1. General description
The ISP1122A is a stand-alone Universal Serial Bus (USB) hub device which
complies with USB Specification Rev. 1.1 . It integrates a Serial Interface Engine
(SIE), hub repeater, hub controller, USB data transceivers and a 3.3 V voltage
regulator. It has a configurable number of downstream ports, ranging from 2 to 5.
The ISP1122A can be bus-powered, self-powered or hybrid-powered. When it is
hybrid-powered the hub functions are powered by the upstream power supply (VBUS),
but the downstream ports are powered by an external 5 Volt supply. The low power
consumption in ‘suspend’ mode allows easy design of equipment that is compliant
with the ACPI™, OnNow™ and USB power management requirements.
The ISP1122A has built-in overcurrent sense inputs, supporting individual and global
overcurrent protection for downstream ports. All ports (including the hub) have
GoodLink™ indicator outputs for easy visual monitoring of USB traffic. The ISP1122A
has a serial I2C-bus interface for external EEPROM access and a reduced frequency
(6 MHz) crystal oscillator. These features allow significant cost savings in system
design and easy implementation of advanced USB functionality into PC peripherals.
2. Features
■High performance USB hub device with integrated hub repeater, hub controller,
Serial Interface Engine (SIE), data transceivers and 3.3 V voltage regulator
■Complies with Universal Serial Bus Specification Rev. 1.1 and ACPI, OnNow and
USB power management requirements
■Configurable from 2 to 5 downstream ports with automatic speed detection
■Internal power-on reset and low voltage reset circuit
■Supports bus-powered, hybrid-powered and self-powered application
■Individual or ganged power switching for downstream ports
■Individual or global port overcurrent protection with built-in sense circuits
■6 MHz crystal oscillator with on-chip PLL for low EMI
■Visual USB traffic monitoring (GoodLink™) for hub and downstream ports
■I2C-bus interface to read vendor ID, product ID and configuration bits from
external EEPROM
■Operation over the extended USB bus voltage range (4.0 to 5.5 V)
■Operating temperature range −40 to +85 °C
■8 kV in-circuit ESD protection for lower cost of external components
■Full-scan design with high test coverage
■Available in 32-pin SDIP, SO and LQFP packages.

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 2 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
3. Ordering information
4. Block diagram
Table 1: Ordering information
Type number Package
Name Description Version
ISP1122AD SO32 plastic small outline package; 32 leads; body width 7.5 mm SOT287-1
ISP1122ANB SDIP32 plastic shrink dual in-line package; 32 leads (400 mil) SOT232-1
ISP1122ABD LQFP32 plastic low profile quad flat package; 32 leads; body 7 x 7 x 1.4 mm SOT358-1
This is a conceptual block diagram and does not include each individual signal.
Fig 1. Block diagram.
pagewidth
MBL169
I2C-BUS
INTERFACE
HUB
REPEATER
ISP1122A
ANALOG
Tx/Rx
D+D−overcurrent
detection
downstream
port 1
LED/
power switch
GoodLink/
POWER SWITCH/
OC DETECT
ANALOG
Tx/Rx
D+D−overcurrent
detection
downstream
port 2
LED/
power switch
GoodLink/
POWER SWITCH/
OC DETECT
ANALOG
Tx/Rx
D+D−overcurrent
detection
downstream
port 3
LED/
power switch
GoodLink/
POWER SWITCH/
OC DETECT
ANALOG
Tx/Rx
D+D−overcurrent
detection
downstream
port 4
LED/
power switch
GoodLink/
POWER SWITCH/
OC DETECT
ANALOG
Tx/Rx
D+D−
full
speed
upstream
port
LED
HUB
GoodLink
ANALOG
Tx/Rx
D+D−overcurrent
detection
self/bus
powered
downstream
port 5
LED/
power switch
GoodLink/
POWER SWITCH/
OC DETECT
HUB
CONTROLLER
PACKET
GENERATOR
GENERAL
PORT
CONTROLLER
END OF
FRAME
TIMERS
PHILIPS
SIE
BIT CLOCK
RECOVERY
PLL
6 MHz
SUPPLY
REGULATOR
VCC
3.3 V
5 V
Vreg(3.3)
SDA
INDV
OPTION
SCL

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 3 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
5. Pinning information
5.1 ISP1122AD (SO32) and ISP1122ANB (SDIP32)
5.1.1 Pinning
5.1.2 Pin description
Fig 2. Pin configuration SO32. Fig 3. Pin configuration SDIP32.
handbook, halfpage
ISP1122AD
MBL163
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
Vreg(3.3)
GND
DM3
DP3
VCC
DM4
DP4
DP2
DM2
DP0
DP1
DM1
DM0
DP5
DM5
INDV/SDA
OPTION/SCL
XTAL2
XTAL1
PSW1/GL1
RESET
PSW5/GL5/GPSW
PSW4/GL4PSW3/GL3
HUBGL
SP/BP
OC5/GOC
PSW2/GL2
OC1
OC2
OC3
OC4
handbook, halfpage
ISP1122ANB
MBL164
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
32
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
Vreg(3.3)
GND
DM3
DP3
VCC
DM4
DP4
DP2
DM2
DP0
DP1
DM1
DM0
DP5
DM5
INDV/SDA
OPTION/SCL
XTAL2
XTAL1
PSW1/GL1
RESET
PSW5/GL5/GPSW
PSW4/GL4PSW3/GL3
HUBGL
SP/BP
OC5/GOC
PSW2/GL2
OC1
OC2
OC3
OC4
Table 2: Pin description for SO32 and SDIP32
Symbol[1] Pin Type Description
Vreg(3.3)[2] 1 - regulated supply voltage (3.3 V ±10%) from internal
regulator; used to connect pull-up resistor on DP0 line
PSW2/GL2[3] 2Omodes 4 to 6: power switch control output for downstream
port 2 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 2 (open-drain, 6 mA); to connect an LED
use a 330 Ωseries resistor
GND 3 - ground supply
DM3 4 AI/O downstream port 3 D−connection (analog)[4]
DP3 5 AI/O downstream port 3 D+connection (analog)[4]
VCC 6 - supply voltage; connect to USB supply VBUS (bus-powered or
hybrid-powered) or to local supply VDD (self-powered)
OC1 7 AI/I overcurrent sense input for downstream port 1 (analog[5])
OC2 8 AI/I overcurrent sense input for downstream port 2 (analog[5])

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 4 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
OC3 9 AI/I overcurrent sense input for downstream port 3 (analog[5])
OC4 10 AI/I overcurrent sense input for downstream port 4 (analog[5])
OC5/GOC[3] 11 AI/I modes 5, 7: overcurrent sense input for downstream port 5
(analog[5])
modes 0, 1, 3: global overcurrent sense input (analog[5])
DM4 12 AI/O downstream port 4 D−connection (analog)[4]
DP4 13 AI/O downstream port 4 D+connection (analog)[4]
SP/BP 14 I selects power mode:
self-powered: connect to VDD (local power supply); also use
this mode for hybrid-powered operation
bus-powered: connect to GND; disable downstream port 5 to
meet supply current requirements[4]
HUBGL 15 O hub GoodLink LED indicator output (open-drain, 6 mA);
to connect an LED use a 330 Ωseries resistor; if unused
connect to VCC via a 10 kΩresistor
PSW3/GL3[3] 16 O modes 4 to 6: power switch control output for downstream
port 3 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 3 (open-drain, 6 mA); to connect an LED
use a 330 Ωseries resistor
PSW4/GL4[3] 17 O modes 4 to 6: power switch control output for downstream
port 4 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 4 (open-drain, 6 mA); to connect an LED
use a 330 Ωseries resistor
PSW5/GL5/
GPSW[3] 18 O mode 5: power switch control output for downstream port 5
(open-drain, 6 mA)
modes 3, 7: GoodLink LED indicator output for downstream
port 5 (open-drain, 6 mA); to connect an LED use a 330 Ω
series resistor
modes 0 to 2: gang mode power switch control output
(open-drain, 6 mA)
XTAL1 19 I crystal oscillator input (6 MHz)
XTAL2 20 O crystal oscillator output (6 MHz)
RESET[2] 21 I reset input (Schmitt trigger); a LOW level produces an
asynchronous reset; connect to VCC for power-on reset
(internal POR circuit)
OPTION/SCL 22 I/O mode selection input; also functions as I2C-bus clock output
(open-drain, 6 mA)
INDV/SDA 23 I/O selects individual (HIGH) or global (LOW) power switching
and overcurrent detection; also functions as bidirectional
I2C-bus data line (open-drain, 6 mA)
DM5 24 AI/O downstream port 5 D−connection (analog)[4]
DP5 25 AI/O downstream port 5 D+connection (analog)[4]
DM1 26 AI/O downstream port 1 D−connection (analog)[6]
DP1 27 AI/O downstream port 1 D+connection (analog)[6]
Table 2: Pin description for SO32 and SDIP32 …continued
Symbol[1] Pin Type Description

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 5 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
[1] Symbol names with an overscore (e.g. NAME) indicate active LOW signals.
[2] The voltage at pin Vreg(3.3) is gated by the RESET pin. This allows fully self-powered operation by
connecting RESET to VBUS (+5 V USB supply). If VBUS is lost upstream port D+ will not be driven.
[3] See Table 4 “Mode selection”.
[4] To disable a downstream port connect both D+and D−to VCC via a 1 MΩresistor; unused ports must
be disabled in reverse order starting from port 5.
[5] Analog detection circuit can be switched off using an external EEPROM, see Table 23; in this case,
the pin functions as a logic input (TTL level).
[6] Downstream ports 1 and 2 cannot be disabled.
DM0 28 AI/O upstream port D−connection (analog)
DP0 29 AI/O upstream port D+connection (analog)
DM2 30 AI/O downstream port 2 D−connection (analog)[6]
DP2 31 AI/O downstream port 2 D+connection (analog)[6]
PSW1/GL1[3] 32 O modes 4 to 6: power switch control output for downstream
port 1 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 1 (open-drain, 6 mA); to connect an LED
use a 330 Ωseries resistor
Table 2: Pin description for SO32 and SDIP32 …continued
Symbol[1] Pin Type Description

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 6 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
5.2 ISP1122ABD (LQFP32)
5.2.1 Pinning
5.2.2 Pin description
Fig 4. Pin configuration LQFP32.
i
dth
ISP1122ABD
MBL165
1
2
3
4
5
6
7
8
24
23
22
21
20
19
18
17
9
10 11 12 13 14 15 16
32 31 30 29 28 27 26 25
DM3 GND PSW2/GL2 Vreg(3.3) PSW1/GL1 DP2 DM2 DP0
DP4
SP/BP
HUBGL
PSW3/GL3 PSW4/GL4
PSW5/GL5/GPSW
XTAL1 XTAL2
DP3
VCC
OC1
DM4
DM0
DP1
DM1
DP5
DM5
INDV/SDA
OPTION/SCL
RESET
OC2
OC3
OC4
OC5/GOC
Table 3: Pin description for LQFP32
Symbol[1] Pin Type Description
Vreg(3.3)[2] 29 - regulated supply voltage (3.3 V ±10%) from internal
regulator; used to connect pull-up resistor on DP0 line
PSW2/GL2[3] 30 O modes 4 to 6: power switch control output for downstream
port 2 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 2 (open-drain, 6 mA); to connect an LED
use a 330 Ωseries resistor
GND 31 - ground supply
DM3 32 AI/O downstream port 3 D−connection (analog)[4]
DP3 1 AI/O downstream port 3 D+connection (analog)[4]
VCC 2 - supply voltage; connect to USB supply VBUS (bus-powered or
hybrid-powered) or to local supply VDD (self-powered)
OC1 3 AI/I overcurrent sense input for downstream port 1 (analog[5])
OC2 4 AI/I overcurrent sense input for downstream port 2 (analog[5])
OC3 5 AI/I overcurrent sense input for downstream port 3 (analog[5])
OC4 6 AI/I overcurrent sense input for downstream port 4 (analog[5])

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 7 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
OC5/GOC[3] 7 AI/I modes 5, 7: overcurrent sense input for downstream port 5
(analog[5])
modes 0, 1, 3: global overcurrent sense input (analog[5])
DM4 8 AI/O downstream port 4 D−connection (analog)[4]
DP4 9 AI/O downstream port 4 D+connection (analog)[4]
SP/BP 10 I selects power mode:
self-powered: connect to VDD (local power supply); also use
this mode for hybrid-powered operation
bus-powered: connect to GND; disable downstream port 5 to
meet supply current requirements[4]
HUBGL 11 O hub GoodLink LED indicator output (open-drain, 6 mA);
to connect an LED use a 330 Ωseries resistor; if unused
connect to VCC via a 10 kΩresistor
PSW3/GL3[3] 12 O modes 4 to 6: power switch control output for downstream
port 3 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 3 (open-drain, 6 mA); to connect an LED
use a 330 Ωseries resistor
PSW4/GL4[3] 13 O modes 4 to 6: power switch control output for downstream
port 4 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 4 (open-drain, 6 mA); to connect an LED
use a 330 Ωseries resistor
PSW5/GL5/
GPSW[3] 14 O mode 5: power switch control output for downstream port 5
(open-drain, 6 mA)
modes 3, 7: GoodLink LED indicator output for downstream
port 5 (open-drain, 6 mA); to connect an LED use a 330 Ω
series resistor
modes 0 to 2: gang mode power switch control output
(open-drain, 6 mA)
XTAL1 15 I crystal oscillator input (6 MHz)
XTAL2 16 O crystal oscillator output (6 MHz)
RESET[2] 17 I reset input (Schmitt trigger); a LOW level produces an
asynchronous reset; connect to VCC for power-on reset
(internal POR circuit)
OPTION/SCL 18 I/O mode selection input; also functions as I2C-bus clock output
(open-drain, 6 mA)
INDV/SDA 19 I/O selects individual (HIGH) or global (LOW) power switching
and overcurrent detection; also functions as bidirectional
I2C-bus data line (open-drain, 6 mA)
DM5 20 AI/O downstream port 5 D−connection (analog)[4]
DP5 21 AI/O downstream port 5 D+connection (analog)[4]
DM1 22 AI/O downstream port 1 D−connection (analog)[6]
DP1 23 AI/O downstream port 1 D+connection (analog)[6]
DM0 24 AI/O upstream port D−connection (analog)
DP0 25 AI/O upstream port D+connection (analog)
Table 3: Pin description for LQFP32 …continued
Symbol[1] Pin Type Description

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 8 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
[1] Symbol names with an overscore (e.g. NAME) indicate active LOW signals.
[2] The voltage at pin Vreg(3.3) is gated by the RESET pin. This allows fully self-powered operation by
connecting RESET to VBUS (+5 V USB supply). If VBUS is lost upstream port D+ will not be driven.
[3] See Table 4 “Mode selection”.
[4] To disable a downstream port connect both D+and D−to VCC via a 1 MΩresistor; unused ports must
be disabled in reverse order starting from port 5.
[5] Analog detection circuit can be switched off using an external EEPROM, see Table 23; in this case,
the pin functions as a logic input (TTL level).
[6] Downstream ports 1 and 2 cannot be disabled.
6. Functional description
The ISP1122A is a stand-alone USB hub with up to 5 downstream ports. The number
of ports can be configured between 2 and 5. The downstream ports can be used to
connect low-speed or full-speed USB peripherals. All standard USB requests from
the host are handled by the hardware without the need for firmware intervention. The
block diagram is shown in Figure 1.
The ISP1122A requires only a single supply voltage. An internal 3.3 V regulator
provides the supply voltage for the analog USB data transceivers.
The ISP1122A supports both bus-powered and self-powered hub operation. When
using bus-powered operation a downstream port cannot supply more than 100 mA to
a peripheral. In case of self-powered operation an external supply is used to power
the downstream ports, allowing a current consumption of max. 500 mA per port.
A basic I2C-bus interface is provided for reading vendor ID, product ID and
configuration bits from an external EEPROM upon a reset.
6.1 Analog transceivers
The integrated transceiver interfaces directly to the USB cables through external
termination resistors. They are capable of transmitting and receiving serial data at
both ‘full-speed’ (12 Mbit/s) and ‘low-speed’ (1.5 Mbit/s) data rates. The slew rates
are adjusted according to the speed of the device connected and lie within the range
mentioned in the USB Specification Rev. 1.1 .
DM2 26 AI/O downstream port 2 D−connection (analog)[6]
DP2 27 AI/O downstream port 2 D+connection (analog)[6]
PSW1/GL1[3] 28 O modes 4 to 6: power switch control output for downstream
port 1 (open-drain, 6 mA)
modes 0 to 3, 7: GoodLink LED indicator output for
downstream port 1 (open-drain, 6 mA); to connect an LED
use a 330 Ωseries resistor
Table 3: Pin description for LQFP32
…continued
Symbol[1] Pin Type Description

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 9 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
6.2 Philips Serial Interface Engine (SIE)
The Philips SIE implements the full USB protocol layer. It is completely hardwired for
speed and needs no firmware intervention. The functions of this block include:
synchronization pattern recognition, parallel/serial conversion, bit (de-)stuffing, CRC
checking/generation, Packet IDentifier (PID) verification/generation, address
recognition, handshake evaluation/generation.
6.3 Hub repeater
The hub repeater is responsible for managing connectivity on a ‘per packet’ basis. It
implements ‘packet signalling’ and ‘resume’ connectivity. Low-speed devices can be
connected to downstream ports. If a low-speed device is detected the repeater will
not propagate upstream packets to the corresponding port, unless they are preceded
by a PREAMBLE PID.
6.4 End-of-frame timers
This block contains the specified EOF1 and EOF2 timers which are used to detect
‘loss-of-activity’ and ‘babble’ error conditions in the hub repeater. The timers also
maintain the low-speed keep-alive strobe which is sent at the beginning of a frame.
6.5 General and individual port controller
The general and individual port controllers together provide status and control of
individual downstream ports. Any port status change will be reported to the host via
the hub status change (interrupt) endpoint.
6.6 GoodLink
Indication of a good USB connection is provided through GoodLink technology. An
LED can be directly connected via an external 330 Ωresistor.
During enumeration the LED blinks on momentarily. After successful configuration of
the ISP1122A, the LED is permanently on. The LED blinks off for 100 ms upon each
successful packet transfer (with ACK). The hub GoodLink indicator blinks when the
hub receives a packet addressed to it. Downstream GoodLink indicators blink upon
an acknowledgment from the associated port. In ‘suspend’ mode the LED is off.
This feature provides a user-friendly indication of the status of the hub, the connected
downstream devices and the USB traffic. It is a useful diagnostics tool to isolate faulty
USB equipment and helps to reduce field support and hotline costs.
6.7 Bit clock recovery
The bit clock recovery circuit recovers the clock from the incoming USB data stream
using a 4×oversampling principle. It is able to track jitter and frequency drift as
specified by the USB Specification Rev. 1.1 .
6.8 Voltage regulator
A 5 to 3.3 V DC-DC regulator is integrated on-chip to supply the analog transceiver
and internal logic. This can also be used to supply the terminal 1.5 kΩpull-up resistor
on the D+line of the upstream connection.

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 10 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
6.9 PLL clock multiplier
A 6 to 48 MHz clock multiplier Phase-Locked Loop (PLL) is integrated on-chip. This
allows for the use of low-cost 6 MHz crystals. The low crystal frequency also
minimizes Electro-Magnetic Interference (EMI). The PLL requires no external
components.
6.10 Overcurrent detection
An overcurrent detection circuit for downstream ports has been integrated on-chip. It
is self-reporting, resets automatically, has a low trip time and requires no external
components. Both individual and global overcurrent detection are supported.
6.11 I2C-bus interface
A basic serial I2C-bus interface (single master, 100 kHz) is provided to read VID, PID
and configuration bits from an external I2C-bus EEPROM (e.g. Philips PCF8582 or
equivalent). At reset the ISP1122A reads 6 bytes of data from the external memory.
The I2C-bus interface timing complies with the standard mode of operation as
described in The I
2
C-bus and how to use it , order number 9398 393 40011.
7. Modes of operation
The ISP1122A has several modes of operation, each corresponding with a different
pin configuration. Modes are selected by means of pins INDV, OPTION and SP/BP,
as shown in Table 4.
[1] Port power switching: logic 0 = ganged, logic 1 = individual.
[2] Power mode: logic 0 = bus-powered, logic 1 = self-powered (or hybrid-powered).
[3] No overcurrent detection.
[4] No power switching.
Table 4: Mode selection
Mode INDV
[1] OPTION SP/BP [2] PSWn/GLn
(n = 1 to 4) PSW5/GL5/GPSW OCn (n = 1 to 4) OC5/GOC
0000GoodLink ganged power inactive global overcurrent
1001GoodLink ganged power inactive global overcurrent
2010GoodLink ganged power inactive[3] inactive[3]
3011GoodLink[4] GoodLink[4] inactive global overcurrent
4100individual power inactive individual
overcurrent inactive
5101individual power individual power individual
overcurrent individual overcurrent
6110individual power inactive inactive[3] inactive[3]
7111GoodLink[4] GoodLink[4] individual
overcurrent individual overcurrent

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 11 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
8. Endpoint descriptions
Each USB device is logically composed of several independent endpoints. An
endpoint acts as a terminus of a communication flow between the host and the
device. At design time each endpoint is assigned a unique number (endpoint
identifier, see Table 5). The combination of the device address (given by the host
during enumeration), the endpoint number and the transfer direction allows each
endpoint to be uniquely referenced.
The ISP1122A has two endpoints, endpoint 0 (control) and endpoint 1 (interrupt).
[1] IN: input for the USB host; OUT: output from the USB host.
8.1 Hub endpoint 0 (control)
All USB devices and functions must implement a default control endpoint (ID = 0).
This endpoint is used by the host to configure the device and to perform generic USB
status and control access.
The ISP1122A hub supports the following USB descriptor information through its
control endpoint 0, which can handle transfers of 64 bytes maximum:
•Device descriptor
•Configuration descriptor
•Interface descriptor
•Endpoint descriptor
•Hub descriptor
•String descriptor.
8.2 Hub endpoint 1 (interrupt)
Endpoint 1 is used by the ISP1122A hub to provide status change information to the
host. This endpoint can be accessed only after the hub has been configured by the
host (by sending the Set Configuration command).
Endpoint 1 is an interrupt endpoint: the host polls it once every 255 ms by sending an
IN token. If the hub has detected no change in the port status it returns a NAK (Not
AcKnowledge) response to this request, otherwise it sends the Status Change byte
(see Table 6).
Table 5: Hub endpoints
Function Ports Endpoint
identifier Transfer type Direction[1] Max. packet size (bytes)
Hub 0: upstream
1 to 5: downstream 0 control OUT 64
IN 64
1 interrupt IN 1

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 12 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
9. Host requests
The ISP1122A handles all standard USB requests from the host via control
endpoint 0. The control endpoint can handle a maximum of 64 bytes per transfer.
Remark: Please note that the USB data transmission order is Least Significant Bit
(LSB) first. In the following tables multi-byte variables are displayed least significant
byte first.
9.1 Standard requests
Table 7 shows the supported standard USB requests. Some requests are explicitly
unsupported. All other requests will be responded to with a STALL packet.
Table 6: Status Change byte: bit allocation
Bit Symbol Description
0 Hub SC a logic 1 indicates a status change on the hub’s upstream port
1 Port 1 SC a logic 1 indicates a status change on downstream port 1
2 Port 2 SC a logic 1 indicates a status change on downstream port 2
3 Port 3 SC a logic 1 indicates a status change on downstream port 3
4 Port 4 SC a logic 1 indicates a status change on downstream port 4
5 Port 5 SC a logic 1 indicates a status change on downstream port 5
6 reserved not used
7 reserved not used
Table 7: Standard USB requests
Request name bmRequestType
byte 0 [7:0]
(Bin)
bRequest
byte 1
(Hex)
wValue
byte 2, 3
(Hex)
wIndex
byte 4, 5
(Hex)
wLength
byte 6, 7
(Hex)
Data
Address
Set Address X000 0000 05 address[1] 00, 00 00, 00 none
Configuration
Get Configuration 1000 0000 08 00, 00 00, 00 01, 00 configuration
value = 01H
Set Configuration (0) X000 0000 09 00, 00 00, 00 00, 00 none
Set Configuration (1) X000 0000 09 01, 00 00, 00 00, 00 none
Descriptor
Get Configuration
Descriptor 1000 0000 06 00, 02 00, 00 length[2] configuration,
interface and
endpoint
descriptors
Get Device Descriptor 1000 0000 06 00, 01 00, 00 length[2] device
descriptor
Get String Descriptor (0) 1000 0000 06 03, 00 00, 00 length[2] language ID
string
Get String Descriptor (1) 1000 0000 06 03, 01 00, 00 length[2] manufacturer
string
Get String Descriptor (2) 1000 0000 06 03, 02 00, 00 length[2] product string

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 13 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
[1] Device address: 0 to 127.
[2] Returned value in bytes.
[3] MSB specifies endpoint direction: 0 = OUT, 1 = IN. The ISP1122A accepts either value.
9.2 Hub specific requests
In Table 8 the supported hub specific requests are listed, as well as some
unsupported requests. Table 9 provides the feature selectors for setting or clearing
port features.
Feature
Clear Device Feature
(REMOTE_WAKEUP) X000 0000 01 01, 00 00, 00 00, 00 none
Clear Endpoint (1)
Feature (HALT/STALL) X000 0010 01 00, 00 81, 00 00, 00 none
Set Device Feature
(REMOTE_WAKEUP) X000 0000 03 01, 00 00, 00 00, 00 none
Set Endpoint (1)
Feature (HALT/STALL) X000 0010 03 00, 00 81, 00 00, 00 none
Status
Get Device Status 1000 0000 00 00, 00 00, 00 02, 00 device status
Get Interface Status 1000 0001 00 00, 00 00, 00 02, 00 zero
Get Endpoint (0) Status 1000 0010 00 00, 00 00/80[3], 00 02, 00 endpoint 0
status
Get Endpoint (1) Status 1000 0010 00 00, 00 81, 00 02, 00 endpoint 1
status
Unsupported
Set Descriptor 0000 0000 07 XX, XX XX, XX XX, XX descriptor;
STALL
Get Interface 1000 0001 0A 00, 00 XX, XX 01, 00 STALL
Set Interface X000 0001 0B XX, XX XX, XX 00, 00 STALL
Synch Frame 1000 0010 0C 00, 00 XX, XX 02, 00 STALL
Table 7: Standard USB requests
…continued
Request name bmRequestType
byte 0 [7:0]
(Bin)
bRequest
byte 1
(Hex)
wValue
byte 2, 3
(Hex)
wIndex
byte 4, 5
(Hex)
wLength
byte 6, 7
(Hex)
Data
Table 8: Hub specific requests
Request name bmRequestType
byte 0 [7:0]
(Bin)
bRequest
byte 1
(Hex)
wValue
byte 2, 3
(Hex)
wIndex
byte 4, 5
(Hex)
wLength
byte 6, 7
(Hex)
Data
Descriptor
Get Hub Descriptor 1010 0000 06 00, 00/29[1] 00, 00 length[2], 00 hub descriptor
Feature
Clear Hub Feature
(C_LOCAL_POWER) X010 0000 01 00, 00 00, 00 00, 00 none
Clear Port Feature
(feature selectors) X010 0011 01 feature[3], 00 port[4], 00 00, 00 none
Set Port Feature
(feature selectors) X010 0011 03 feature[3], 00 port[4], 00 00, 00 none

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 14 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
[1] USB Specification Rev. 1.0 uses 00H, USB Specification Rev. 1.1 specifies 29H.
[2] Returned value in bytes.
[3] Feature selector value, see Table 9.
[4] Downstream port identifier: 1 to N with N = number of enabled ports (2 to 5).
Status
Get Hub Status 1010 0000 00 00, 00 00, 00 04, 00 hubstatusand
status change
field
Get Port Status 1010 0011 00 00, 00 port[4], 00 04, 00 port status
Unsupported
Get Bus Status 1010 0011 02 00, 00 port[4], 00 01, 00 STALL
Clear Hub Feature
(C_OVER_CURRENT) X010 0000 01 01, 00 00, 00 00, 00 STALL
Set Hub Descriptor 0010 0000 07 XX, XX 00, 00 3E, 00 STALL
Set Hub Feature
(C_LOCAL_POWER) X010 0000 03 00, 00 00, 00 00, 00 STALL
Set Hub Feature
(C_OVER_CURRENT) X010 0000 03 01, 00 00, 00 00, 00 STALL
Table 8: Hub specific requests
…continued
Request name bmRequestType
byte 0 [7:0]
(Bin)
bRequest
byte 1
(Hex)
wValue
byte 2, 3
(Hex)
wIndex
byte 4, 5
(Hex)
wLength
byte 6, 7
(Hex)
Data
Table 9: Port feature selectors
Feature selector name Value (Hex) Set feature Clear feature
PORT_CONNECTION 00 not used not used
PORT_ENABLE 01 not used disables a port
PORT_SUSPEND 02 suspends a port resumes a port
PORT_OVERCURRENT 03 not used not used
PORT_RESET 04 resets and enables a
port not used
PORT_POWER 08 powers on a port powers off a port
PORT_LOW_SPEED 09 not used not used
C_PORT_CONNECTION 10 not used clears port connection
change bit
C_PORT_ENABLE 11 not used clears port enable
change bit
C_PORT_SUSPEND 12 not used clears port suspend
change bit
C_PORT_OVERCURRENT 13 not used clears port overcurrent
change bit
C_PORT_RESET 14 not used clears port reset
change bit

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 15 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
9.3 Descriptors
The ISP1122A hub controller supports the following standard USB descriptors:
•Device
•Configuration
•Interface
•Endpoint
•Hub
•String.
Table 10: Device descriptor
Values in square brackets are optional.
Offset
(bytes) Field name Size (bytes) Value (Hex) Comments
0 bLength 1 12 descriptor length = 18 bytes
1 bDescriptorType 1 01 type = DEVICE
2 bcdUSB 2 10, 01
USB Specification Rev. 1.1
4 bDeviceClass 1 09 HUB_CLASSCODE
5 bDeviceSubClass 1 00 -
6 bDeviceProtocol 1 00 -
7 bMaxPacketSize0 1 40 packet size = 64 bytes
8 idVendor 2 CC, 04 Philips Semiconductors vendor ID
(04CC); can be customized using an
external EEPROM (see Table 23)
10 idProduct 2 22, 11 ISP1122A product ID; can be
customized using an external
EEPROM (see Table 23)
12 bcdDevice 2 01, 01 device release 1.1; silicon revision
increments this value
14 iManufacturer 1 00 no manufacturer string (default)
[01] manufacturer string enabled
(using an external EEPROM)
15 iProduct 1 00 no product string (default)
[02] product string enabled
(using an external EEPROM)
16 iSerialNumber 1 00 no serial number string
17 bNumConfigurations 1 01 one configuration

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 16 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
[1] Selected by input SP/BP.
[2] Value in units of 2 mA.
Table 11: Configuration descriptor
Values in square brackets are optional.
Offset
(bytes) Field name Size (bytes) Value (Hex) Comments
0 bLength 1 09 descriptor length=9bytes
1 bDescriptorType 1 02 type = CONFIGURATION
2 wTotalLength 2 19, 00 total length of configuration, interface
and endpoint descriptors (25 bytes)
4 bNumInterfaces 1 01 one interface
5 bConfigurationValue 1 01 configuration value = 1
6 iConfiguration 1 00 no configuration string
7 bmAttributes 1 E0 self-powered with remote wake-up[1]
A0 bus-powered with remote wake-up[1]
8 MaxPower[2] 1 32 100 mA (default)
[00] 0 mA (using an external EEPROM)
[FA] 500 mA (using an external EEPROM)
Table 12: Interface descriptor
Offset
(bytes) Field name Size (bytes) Value (Hex) Comments
0 bLength 1 09 descriptor length=9bytes
1 bDescriptorType 1 04 type = INTERFACE
2 bInterfaceNumber 1 00 -
3 bAlternateSetting 1 01 no alternate setting
4 bNumEndpoints 1 01 status change (interrupt) endpoint
5 bInterfaceClass 1 09 HUB_CLASSCODE
6 bInterfaceSubClass 1 00 -
7 bInterfaceProtocol 1 00 no class-specific protocol
8 bInterface 1 00 no interface string
Table 13: Endpoint descriptor
Offset
(bytes) Field name Size (bytes) Value (Hex) Comments
0 bLength 1 07 descriptor length=7bytes
1 bDescriptorType 1 05 type = ENDPOINT
2 bEndpointAddress 1 81 endpoint 1, direction: IN
3 bmAttributes 1 03 interrupt endpoint
4 wMaxPacketSize 2 01, 00 packet size = 1 byte
6 bInterval 1 FF polling interval (255 ms)

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 17 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
[1] ISP1122A always reports power management status on an individual basis, even for ganged/global
modes. This is compliant with USB Specification Rev. 1.1 .
[2] Condition with no overcurrent detection is reported to the host.
[3] Value in units of 2 ms.
[1] Unicode encoded string.
Table 14: Hub descriptor
Values in square brackets are optional.
Offset
(bytes) Field name Size (bytes) Value (Hex) Comments
0 bDescLength 1 09 descriptor length=9bytes
1 bDescriptorType 1 29 type = HUB
2 bNbrPorts 1 05 to 02 number of enabled downstream ports;
selectable by DP/DM strapping
3 wHubCharacteristics 2 09, 00 individual power switching[1],
overcurrent protection active
(modes 0, 1, 3, 4, 5, 7)
11, 00 individual power switching[1], no
overcurrent protection (modes 2, 6)[2]
5 bPwrOn2PwrGood[3] 1 32 100 ms (default; modes 0, 1, 2, 4, 5, 6)
00 0 ms (default; modes 3, 7)
[FA] 500 ms (using an external EEPROM;
modes 0, 1, 2, 4, 5, 6); see Table 23
6 bHubContrCurrent 1 64 maximum hub controller current
(100 mA)
7 DeviceRemovable 1 00 all devices removable
8 PortPwrCtrlMask 1 FF must be all ones for compatibility with
USB Specification Rev. 1.0
Table 15: String descriptors
String descriptors are optional and therefore disabled by default; they can be enabled through
an external EEPROM.
Offset
(bytes) Field name Size (bytes) Value (Hex) Comments
String descriptor (0): language ID string
0 bLength 1 04 descriptor length=4bytes
1 bDescriptorType 1 03 type = STRING
2 bString 2 09, 04 LANGID code zero
String descriptor (1): manufacturer string
0 bLength 1 2E descriptor length = 46 bytes
1 bDescriptorType 1 03 type = STRING
2 bString 44 UC[1] “Philips Semiconductors”
String descriptor (2): product string
0 bLength 1 10 descriptor length = 16 bytes
1 bDescriptorType 1 03 type = STRING
2 bString 14 UC[1] “ISP1122”

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 18 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
9.4 Hub responses
This section describes the hub responses to requests from the USB host.
9.4.1 Get device status
The hub returns 2 bytes, see Table 16.
9.4.2 Get configuration
The hub returns 1 byte, see Table 17.
9.4.3 Get interface status
The hub returns 2 bytes, see Table 18.
9.4.4 Get hub status
The hub returns 4 bytes, see Table 19.
Table 16: Get device status response
Bit # Function Value Description
0 self-powered 0 bus-powered
1 self-powered
1 remote wake-up 0 no remote wake-up
1 remote wake-up enabled
2 to 15 reserved 0 -
Table 17: Get configuration response
Bit # Function Value Description
0 configuration value 0 device not configured
1 device configured
1 to 7 reserved 0 -
Table 18: Get interface status response
Bit # Function Value Description
0 to 15 reserved 0 -
Table 19: Get hub status response
Bit # Function Value Description
0 local power source 0 local power supply good
1 local power supply lost
1 overcurrent indicator 0 no overcurrent condition
1 hub overcurrent condition detected
2 to 15 reserved 0 -
16 local power status change 0 no change in local power status
1 local power status changed
17 overcurrent indicator change 0 no change in overcurrent condition
1 overcurrent condition changed
18 to 31 reserved 0 -

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 19 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
9.4.5 Get port status
The hub returns 4 bytes. The first 2 bytes contain the port status bits (wPortStatus,
see Table 20). The last 2 bytes hold the port status change bits (wPortChange, see
Table 21).
Table 20: Get port status response (wPortStatus)
Bit # Function Value Description
0 current connect status 0 no device present
1 device present on this port
1 port enabled/disabled 0 port disabled
1 port enabled
2 suspend 0 port not suspended
1 port suspended
3 overcurrent indicator 0 no overcurrent condition
1 overcurrent condition detected
4 reset 0 reset not asserted
1 reset asserted
5 to 7 reserved 0 -
8 port power 0 port powered off
1 port power on
9 low-speed device attached 0 full-speed device attached
1 low-speed device attached
10 to 15 reserved 0 -
Table 21: Get port status response (wPortChange)
Bit # Function Value Description
0 connect status change 0 no change in current connect status
1 current connect status changed
1 port enabled/disabled
change 0 no port error
1 port disabled by a port error
2 suspend change 0 no change in suspend status
1 resume complete
3 overcurrent indicator change 0 no change in overcurrent status
1 overcurrent indicator changed
4 reset change 0 no change in reset status
1 reset complete
5 to 15 reserved 0 -

Philips Semiconductors ISP1122A
USB stand-alone hub
Product data Rev. 03 — 30 October 2001 20 of 48
9397 750 08958 © Koninklijke Philips Electronics N.V. 2001. All rights reserved.
9.4.6 Get configuration descriptor
The hub returns 25 bytes containing the configuration descriptor (9 bytes, see
Table 11), the interface descriptor (9 bytes, see Table 12) and the endpoint descriptor
(7 bytes, see Table 13).
9.4.7 Get device descriptor
The hub returns 18 bytes containing the device descriptor, see Table 10.
9.4.8 Get hub descriptor
The hub returns 9 bytes containing the hub descriptor, see Table 14.
9.4.9 Get string descriptor (0)
The hub returns 4 bytes containing the language ID, see Table 15.
9.4.10 Get string descriptor (1)
The hub returns 46 bytes containing the manufacturer name, see Table 15.
9.4.11 Get string descriptor (2)
The hub returns 16 bytes containing the product name, see Table 15.
10. I2C-bus interface
A simple I2C-bus interface is provided in the ISP1122A to read customized vendor ID,
product ID and some other configuration bits from an external EEPROM. The
interface supports single master operation at a nominal bus speed of 93.75 kHz.
The I2C-bus interface is intended for bidirectional communication between ICs via two
serial bus wires, SDA (data) and SCL (clock). Both lines are driven by open-drain
circuits and must be connected to the positive supply voltage via pull-up resistors.
10.1 Protocol
The I2C-bus protocol defines the following conditions:
•Bus free: both SDA and SCL are HIGH
•START: a HIGH-to-LOW transition on SDA, while SCL is HIGH
•STOP: a LOW-to-HIGH transition on SDA, while SCL is HIGH
•Data valid: after a START condition, data on SDA are stable during the HIGH
period of SCL; data on SDA may only change while SCL is LOW.
Each device on the I2C-bus has a unique slave address, which the master uses to
select a device for access.
The master starts a data transfer using a START condition and ends it by generating
a STOP condition. Transfers can only be initiated when the bus is free. The receiver
must acknowledge each byte by means of a LOW level on SDA during the ninth clock
pulse on SCL.
For detailed information please consult The I
2
C-bus and how to use it ., order number
9398 393 40011.