NXP Semiconductors ISP1562, ISP1563 User Manual

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Designing a Hi-Speed USB host PCI adapter using the ISP1562, ISP1563

Rev. 04 — 1 November 2007

Application note

Document information






isp1562; isp1563; usb; universal serial bus; host; pci adapter




This document contains a description of the ISP1562/3 application


schematics and the PCB design recommendations.



NXP Semiconductors











Designing a Hi-Speed USB host PCI adapter using ISP1562/63

Revision history

























Fourth revision. Corrected typo in Section 4: it is 2.5 inches ± 0.1 inch, not ± 1 inch.







Last line of Section 3.4.





Third revision. Updated Fig 6.










Second revision. Updated Section 5.





First release.










Contact information

For additional information, please visit: http://www.nxp.com

For sales office addresses, please send an email to: salesaddresses@nxp.com



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Designing a Hi-Speed USB host PCI adapter using ISP1562/63

1. Introduction

The ISP1562 and the ISP1563 are Hi-Speed Universal Serial Bus (USB) host controllers (HCs) that can be directly connected to a standard 32-bit, 33 MHz PCI bus. For the rest of this document, they will be known as ‘ISP1562/3’. The ISP1562/3 complies with PCI Local Bus Specification Rev. 2.2 and PCI Bus Power Management Interface Specification Rev. 1.1. No additional logic is required to implement a complete Hi-Speed USB host controller solution on Peripheral Component Interconnect (PCI).

Adapter cards based on the ISP1562/3 implement three functions: function 0 and function 1 for OHCI1 and OHCI2, and function 2 for EHCI. According to PCI Local Bus Specification, each physical PCI device may incorporate one to eight separate functions (logical devices). Each function contains its own memory-mapped individually addressable configuration space of 256 bytes, containing configuration registers.

The configuration registers of the ISP1562/3 are used by the system’s BIOS and the operating system to detect the presence of the respective functions, that is, Vendor ID (VID) and Product ID (PID), to determine the necessary resource requirements, that is, memory and I/O space, interrupt lines, and so on, and for specific capabilities.

A set of on-chip ‘operational’ registers is also defined for each of the three host controllers implemented in the ISP1562/3. The respective host controller device driver interacts with these registers to implement the USB functionality and the legacy support. A detailed description of configuration registers and operational registers can be found in the ISP1562 and ISP1563 data sheets.

The ISP1562/3 implements two internal ‘power wells’, VDD and VDDX, to benefit from the PCI VAUX = 3.3 V dedicated power source, which is present on the PCI connector (pin A14) even when PCI VCC = 3.3 V is off. This enables the ISP1562/3 PME# signal to be asserted and activates the wake-up logic of the motherboard, even if the rest of the system is powered down; for example, in S3cold system standby mode. This is applicable mainly to onboard (desktop) or mobile designs, but not applicable to PCI add-on cards because the PCI +5 V, used for VBUS, is also off during S3cold.

The ISP1562/3 may use PCI VAUX to power its four internal transceivers connected to the ISP1562/3 VDDA_AUX (analog), and also the clock circuitry, port router, root hub and Power Management Event (PME#) logic connected to the ISP1562/3 VCC(I/O)_AUX (digital).

For details on implementation of the PCB design, see Section 4.

The power management capabilities enabled by using PCI VAUX allow system designers to meet the governmental energy regulations that are becoming increasingly essential worldwide: Energy Star/USA: 30 W standby, White Swan/Europe: 5 W standby, Blue Angel/Europe: 5 W standby.

This document provides a description of the application schematics and the PCB design recommendations.

2. ISP1562/3 initialization

The following sequence is required during the ISP1562/3 initialization, for correct functionality:

1.Register HcRhDescriptorA = 902h. This means that bit PSM = 1b.

2.Register HcControl = 680h. This means that bits HCFS[1:0] = 10b (operational mode).



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Designing a Hi-Speed USB host PCI adapter using ISP1562/63

3. Register HcRhStatus = 18000h. This implies that bit LPSC = 1b (port powered).

Microsoft Windows 2000, Windows XP and Linux drivers normally use this sequence. The order of the steps may, however, be reversed in Windows CE default drivers so changes are required for normal functionality.

3. Description of the application schematics

The schematics (see Section 5) contain a complete implementation of the ISP1562/3 and allow testing of all its features in different types of design: PCI add-on card, onboard design in standard desktop or mobile solution.

In the case of a standard PCI add-on card design, some simplifications to the schematics can be done, as described here. Some features will not be normally used in a standard

PCI add-on card. For example: The legacy support, wake-up from S3cold (no external +5 V input for VBUS) and the alternative 48 MHz clock input. All these alternatives,

however, are included in the schematics and are described in this document.

3.1 Distribution of power sources and power management support

As shown in the schematics (see Section 5), a simple solution by using one jumper (JP1)

may be adopted to choose between PCI VCC = 3.3 V or PCI VAUX = 3.3 V as the main power source for the ISP1562/3. Power source PCI VAUX = 3.3 V is introduced in PCI

Local Bus Specification Revision 2.2. It allows powering an add-on card and generation of the PME# signal, even if the system is in a deep power management state and PCI VCC is off. An alternative solution to using a jumper may be a simple circuit containing a pair of MOSFET transistors that allows to detect the presence of PCI VAUX = 3.3 V and automatic selection of the input voltage.

Selection of PCI VCC = +3.3 V must be the default position of jumper JP1 in the case of a standard add-on card design. The other possible position of JP1 selects PCI VAUX = 3.3 V for complete Power Management tests, including S3cold in the case of on-motherboard or notebook. Note that pins 3, 77, 98 and 100 of the ISP1562, and pins 6, 12 and 95 of the

ISP1563 are connected to the PCB VCC(I/O)_AUX power plane and pins 86 and 93 of the ISP1562, and pins 104, 111, 120 and 128 of the ISP1563 are connected to the PCB

VDDA_AUX power plane. Each of these planes is separated from PCI VAUX by its own set of inductors and decoupling capacitors.

Although most of the motherboards provide the PCI VAUX power source in all system power management modes, including S3cold, the PCI +5 V power supply is simultaneously interrupted with PCI VCC = +3.3 V.

In certain standby modes (S3cold), the devices connected to USB ports will not be powered once the +5 V power is removed because the VBUS voltage present on USB

connectors is normally derived from the PCI +5 V power supply. Therefore, PCI VAUX is not useful in the case of a standard PCI add-on card implementation for a system wakeup from S3cold. It is, however, a very useful feature for onboard and mobile application designs because it allows additional considerable power savings and also wakes up the

system by using a USB device. The system wake-up from S3cold, generated from a USB device, for example, USB mouse or USB keyboard, connected to the ISP1562/3 host

controller must be supported in system’s BIOS, hardware (a continuous +5 V must be supplied to VBUS) and operating system drivers.

To be able to test the remote wake-up, especially, from those power management states

in which the +5 V power source on PCI is not present, for example, S3cold, a special connector (J1) is added for an external +5 V source. Any external independent power



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Designing a Hi-Speed USB host PCI adapter using ISP1562/63

supply that provides +5 V ± 5 % @ 2 A stabilized can be used. For example, a standard hub power supply.

Note the distribution of pull-up resistors in the recommended schematics. For example, to achieve correct functionality, it is recommended that you connect the pull-up resistors placed on the PWEn_N and OCn_N input signals of the power switch, for example, MIC2026, to DVAUX NET, maintaining a good condition of these signals even when +3.3 V and +5 V are off. The ‘fault flag’ pins (OCn_N) of MIC2026 are open-drain and require the presence of pull-up resistors. A 100 nF capacitor is used on each OCn_N signal to prevent false fault conditions.

CLKRUN# is implemented in the ISP1562 on pin 42 and in the ISP1563 on pin 52. This signal is targeted mainly for mobile system designs. CLKRUN is an I/O pin. It is used by the system to safely turn-off the PCI CLK for power saving, with acknowledgment from the ISP1562/3 according to a predefined protocol. In the case of the PCI adapter card design, CLKRUN# must always be LOW because it is not present in the PCI connector. CLKRUN# may directly be connected to GND. For details on CLKRUN# function, refer to

PCI Mobile Design Guide Version 1.1.

3.2 Input clock: applies only to the ISP1563

You can use either of the following as clock input:

A 12 MHz crystal; the default recommended solution for best ElectroMagnetic Interference (EMI) results.

A 48 MHz oscillator; this may be a useful alternative, typically, in the case of onmotherboard design.

Both solutions for the input clock are shown in the schematics.

To use a 48 MHz clock as input, connect the clock signal to the ISP1563 pin 86 (XTAL1), pin 87 (XTAL2) can be left open, and pin 121 (SEL48M) must be pulled up as shown in the schematics.

In an add-on card configuration, normally, the 12 MHz crystal is used. In such a case, oscillators OSC2 and R45 are not necessary. Also, pin 121 (SEL48M) must directly be connected to GND. Another possibility is using a 12 MHz clock as an input. In this case, the 12 MHz-clock signal is directly connected to the ISP1563 pin 86 (XTAL1). This is similar to the case in which the 48 MHz clock is used; however, the ISP1563 pin 121 must still be connected to GND.

3.3 Selecting the number of ports: applies only to the ISP1563

The selection of the number of ports, 2 or 4, is done using the SEL2PORTS signal (ISP1563 pin 5). It must be pulled to LOW, that is, connected to GND, for normal use of all four ports. If SEL2PORTS is HIGH, only two ports, that is, port 1 and port 2, are enabled; one port from each OHCI will be used in this case for performance improvement. Details regarding the power consumption and possible power savings in a two-port configuration can be found in the ISP1563 data sheet.

3.4 Subsystem vendor ID and subsystem device ID

The ISP1562/3 allows loading of the Subsystem Vendor ID (VID) and the Subsystem Device ID (DID) for both EHCI and OHCI from an external EEPROM. Loading of these values in the configuration registers of the ISP1562/3 will occur only if a value of 15h is found in byte 7 of the EEPROM. The necessary signals, I2C-bus clock and I2C-bus data,



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Designing a Hi-Speed USB host PCI adapter using ISP1562/63

are defined on pins 96 (SCL) and 97 (SDA) of the ISP1562, and pins 122 (SCL) and 123 (SDA) of the ISP1563, respectively. When not in use, these signals must be connected to ground using a pull-down resistor, typically 10 kΩ.

3.5 Legacy support: applies only to the ISP1563

Legacy signals, IRQ1, IRQ12, A20OUT, KBIRQ1, MUIRQ12 and SMI#, are not normally used on a PCI add-on card design. In this case, the MUIRQ12 and KBIRQ1 input signals must be connected to GND. The other signals that are mentioned in this category (that are outputs) can be left open.

Details on legacy signals and a block diagram showing correct connection of these signals in the case of onboard design can be found in ISP1563 Eval Board User Manual (UM10066).

3.6 Overcurrent protection

The ISP1562/3 implements the digital overcurrent protection scheme.

The recommended solution to implement an external overcurrent protection is a standard power switch with integrated overcurrent detection, such as:

LM3526 and MIC2526 (2 ports), or

LM3544 (4 ports).

The overcurrent protection logic of the ISP1562/3 uses the following two pins for each USB port:

PWEn_N: It is used to enable or disable the respective external port power switch. For example, MIC2526 and LM3526.

OCn_N: It is an input on which a fault condition on the respective USB port is signaled to the ISP1562/3 by the external port power-switching device.

The fault condition that is usually signaled by an external power-switching device can be an overcurrent or a thermal shutdown. The port power-switching integrated devices commonly implement a delay of 1 ms to 3 ms to prevent false OC_N reporting because of inrush currents, when plugging a USB device.

Once a fault condition is received, it will be detected by the operating system and the respective device driver will disable the port power switch by programming the Port Power (PP) bit in the PORTSC register. This device driver is the OHCI driver in the case of an Original USB device to create the fault condition, or the EHCI driver in the case of a Hi-Speed USB device to create the overcurrent condition. This is according to the USB port allocation at the moment when the OC# signal was asserted.

A possible alternative is to use a resettable fuse on each port. This has the advantage of simplicity. It, however, does not inform the operating system of the fault condition and, therefore, no message is generated to inform the user. The resettable fuse will continue to protect the port by switching ‘on or off’ as long as the overcurrent condition persists.

A possible enhancement of this scheme is connecting VBUS to the OCn_N input of the ISP1562/3 to detect the OCn_N condition, the first time VBUS is cut-off a LOW level will appear on the OCn_N pin.

Using only an external PMOS transistor for overcurrent protection is not possible because the ISP1562/3 does not implement the analog overcurrent protection (not measuring the current through the transistor).



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