8.0 DC Parameters ............................................................................................................................................................................. 43
9.0 AC Specifications .......................................................................................................................................................................... 47
11.0 Revision History .......................................................................................................................................................................... 51
The Microchip Web Site ...................................................................................................................................................................... 54
Customer Change Notification Service ............................................................................................................................................... 54
Customer Support ............................................................................................................................................................................... 54
Product Identification System ............................................................................................................................................................. 55
2014-2015 Microchip Technology Inc.
DS00001578C-page 3
USB2642
1.0
1.1
OVERVIEW
Introduction
The USB2642 offers a USB 2.0 compliant, versatile, cost-effective and energy-efficient hi-speed hub controller with 2
downstream USB ports and an SD/MMC flash media card interface. The dedicated flash media reader is internally
attached to a 3rd downstream port of the hub as a USB compound device. This combo solution supports today’s popular
multi-format flash media card formats. The flash media interface can support sustained transfer rates exceeding 35 MB/
s if the media and host support those rates.
The USB2642 also provides I
2
C over USB. The I
2
C bridge allows for control of any I
2
C device operating at 50kHz clock.
The USB2642 will attach to an upstream port as either a full-speed or full-/hi-speed hub. The hub supports low-speed,
full-speed, and hi-speed (if operating as a full-/hi-speed hub) downstream devices on all of the enabled downstream
ports.
All required resistors on the USB ports are integrated into the hub. This includes all series termination resistors on D+
and D- pins and all required pull-down and pull-up resistors. The over-current sense inputs for the downstream facing
ports have internal pull-up resistors.
The USB2642 includes programmable features such as:
PortMap
which provides flexible port mapping and disable sequences. The downstream ports of a USB2642 hub can
be reordered or disabled in any sequence to support multiple platform designs with minimum effort. For any port that is
disabled, the USB2642 automatically reorders the remaining ports to
match the USB host controller’s port numbering scheme.
PortSwap
which adds per-port programmability to USB differential-pair
pin locations. PortSwap allows direct alignment of USB signals (D+/D-)
to connectors avoiding uneven trace length or crossing of the USB differ-
ential signals on the PCB.
PHYBoost
which enables four programmable levels of USB signal drive
strength in downstream port transceivers. PHYBoost attempts to restore
USB signal integrity. The diagram on the right shows an example of Hi-
Speed USB eye diagrams before (PHYBoost at 0%) and after (PHYBoost
at 12%) signal integrity restoration in a compromised system environ-
ment.
2014-2015 Microchip Technology Inc.
DS00001578C-page 4
USB2642
1.2
1.2.1
•
•
•
•
•
•
Device Features
HARDWARE FEATURES
Single-chip hub, flash media controller, and I
2
C device control over USB
Supports commercial (0 °C to +70 °C) and industrial (-40 °C to +85 °C) temperature ranges
Transaction Translator (TT) in the hub supports operation of FS and LS peripherals
Full power management with individual or ganged power control of each downstream port
Optional support for external firmware access via SPI
Code execution via SPI ROM which must meet the following qualifications:
- 60 MHz operation support
- Single bit or dual bit mode support
- Mode 0 or mode 3 SPI support
Compliant with the following flash media card specifications:
• Secure Digital 2.0
- SDSC, SDHC, and SDXC
- microSD and reduced form factor media
- Supports storage addressability of up to 2TB
• MultiMediaCard 4.2
- 1/4/8 bit
- Includes support for eMMC devices
• Control of I
2
C device using the I
2
C over USB bridge
• Supports internal regulator for 1.8 V core operation
• Supports external regulator for 1.8 V core operation
1.2.2
CONFIGURABLE FEATURES
Default configuration is loaded by USB2642 following a reset. The USB2642 may also be configured by an external I
2
C
EEPROM or external SPI ROM flash, where the following features are supported:
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Customizable vendor ID, product ID, and device ID
12-hex digits maximum for the serial number string
29-character manufacturer ID and product strings for flash media reader/writer
Compound device support on a port-by-port basis a port is permanently hardwired to a downstream USB periph-
eral device
Select over-current sensing and port power control on an individual or ganged (all ports together) basis to match
the circuit board component selection
Port power control and over-current detection/delay features
Configure the delay time for filtering the over-current sense inputs
Configure the delay time for turning on downstream port power
Bus- or self-powered selection
Hub port disable of non-removable configurations
Flexible port mapping and disable sequencing supports multiple platform designs
Programmable USB differential-pair pin location selection eases PCB layout by aligning USB signal lines directly
to connectors
Programmable USB signal drive strength improves USB signal integrity using 4 levels of signal drive strength
Indicate the maximum current that the 2-port hub consumes from the USB upstream port
Manage the maximum current required for the hub controller
中国 北京—— Analog Devices, Inc. （纽约证券交易所代码 : ADI ），全球领先的高性能信号处理解决方案供应商，最新推出两款模拟输出驱动器—— AD5750 和 AD5751 ，能显著提高过程控制应用的效率和可靠性，包括那些在高恒流电压和高温条件下工作的过程控制应用。这两款器件基于 ADI 公司的 iCMOS ™工业工艺技术，输出驱动器的精度...[详细]
DIY/开源硬件专区
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
