2
T7906E
Rev. A
–
27-Aug.-01
The interfaces of the T7906E such as the FIFO, UART, ADC/DAC and memory inter-
face are accessed by a simple read or write operation to the corresponding interface
address. In the case of FIFO, Host, UART and memory interface, a packet oriented
access is also possible (meaning transferring multiple bytes with a single command). In
case a communication memory
is connected to the T7906E, this can be read and written to via the link specific registers.
The IEEE-1355 links can support a range of communication speeds, which are pro-
grammed by writing to registers. At reset all links are configured to run at the base
speed of 10 Mbits/sec. Only the transmission speed of a link is programmed as recep-
tion is asynchronous. This means that links running at different speeds can be
connected, provided that each device is capable of receiving at the speed of the con-
nected transmitter.
Introduction
Connecting a non-intelligent node to a processing element requires not only the commu-
nication controller, but usually a controlling instance for the communication circuitry. The
latter has to be configured for settings like bit rate, packet sizes, handshake protocols
etc. Should the non-intelligent node require remote control via commands, usually a
second link, dedicated for commands is introduced. Using an IEEE-1355 link for that
purpose eliminates the need for separate data and control paths, since the communica-
tion controller can differentiate between the two entities. In addition, it can be remotely
configured, can execute simple commands and provides special I/O pins to control the
interface unit.
The T7906E provides one IEEE-1355 serial communication link together with additional
features to support non-intelligent nodes as well as to control ADC and DAC converters.
The T7906E is targeted at two main applications areas:
Embedded systems
Communication device for processor systems
Embedded systems
The main application targets of the T7906E are modules and units without any built-in
communication features, such as special image compression chips, application specific
programmable logic or mass memory. The T7906E is perfectly suited to be used on
"non-intelligent" modules such as A/D-converter or sensor interfaces, due to its "control
by link" feature and system control facilities. In addition, its fault tolerance feature make
the device very interesting for many critical industrial measurement and control systems.
Example applications of the T7906E as communication and system controller on an
interface node consisting of an ADC and DAC and one where the T7906E is connected
to four banks of memory are given in the figures below: