Product Brief
TransDimension
TD243
interrupt event may be delayed inside the TD243, and be bundled with others to further reduce the number of
interrupt occurrences.
*
Even though invisible to the high level software, low level interrupts are necessary to handle 4KByte internal data RAM.
Memory blocks:
The Host Controller Logic, the Peripheral Controller logic, the microprocessor, and the DMA logic
are all entitled to have access to the memory blocks for data and control. A RAM Arbiter sequences all RAM
access.
Register banks:
There are 3 register banks used for System Configuration, Host Control, and Peripheral Control.
Host Negotiation Protocol (HNP):
The user may select one of two HNP types supported in the TD243. The user
simply selects software or hardware HNP, depending on their application, with each type of HNP having its own
merits. Hardware HNP is a built-in state machine, which reduces microprocessor interrupts, whereas, software
HNP is maintained and manipulated in the software space and provides an extra option to the user.
Both types of HNP, when enabled, will support negotiation with an attached OTG device, in order to determine in
which role (A-device or B-device) the TD243 will operate as, in a session. The TD243 contains the required analog
components (comparators, charge pump, etc.) and digital logic to support the operation. The microprocessor
interfaced to the TD243 can also disable this negotiation process, and configure the Dual-Role Device port of the
TD243 to operate as a host or peripheral. HNP may only be implemented in conjunction with a Mini-AB receptacle.
Session Request Protocol (SRP):
The USB OTG specification is positioned to service mobile products that are
battery powered. The SRP protocol allows the A-device to conserve power by turning the USB VBus signal off
depending on whether there is USB traffic. The B-device will have the capability to initiate bus activity via SRP and
hence the A-device will be capable of responding to this via SRP. The TD243 On-The-Go port fully complies to the
SRP protocol as described and defined in the USB On-The-Go specification.
Operational Modes:
The TD243 can be operated in different modes via software configuration:
Port 1
On-The-Go
OTG
Port 2
Host
Port 3
Host
Application
OTG application and two host ports
(concurrent OTG/Host operation supported. The OTG
port may behave in either host or peripheral modes and
dynamically switch between roles through the HNP or
when directed by a user change of USB cable
connection)
Host Only
Host/Peripheral
Host
Peripheral
Host
Host
Host
Host
Host only controller with three ports
Two host and one peripheral port
(concurrent host and peripheral operation supported)
5V charge pump:
The TD243 charge pump generates +5 volts (VBUS) of up to 12mA from its 3.3V power supply.
If an external 5V is available in the system, the internal TD243 charge pump may be disabled, and the TD243 will
still be able to provide full control (switch on/off, pulsing, etc.) of the VBUS. There are several modes to consider
when considering power:
Microprocessor interface:
The TD243 is a memory mapped device and can easily interface, gluelessly, to the
system bus of most popular microprocessors, CISC, RISC and DSP’s including but not limited to x86, Intel XScale
& StrongARM, Hitachi SH3, Fujitsu SPARCLite, NEC and Toshiba MIPS, ARM7, ARM9, Motorola PowerPC,
ColdFire and Dragonball, among others. Reference designs and evaluation boards for some of these processors
are available with new designs being added and tailored to fit particular customer needs.
Software support:
TransDimension is a leader in the USB embedded market, bringing both software and silicon
to its customers. The company provides development and support packages and a wide spectrum of USB host and
On-The-Go software support in C source code to reduce development cost and time to market for its customers.
Software for a variety of operating systems is fully tested and supported to easily interoperate with the above listed
microprocessors. TransDimension is a Microsoft Windows embedded partner.
TransDimension Inc. — Proprietary
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OXFORD [ OXFORD SEMICONDUCTOR ]
