Glossary
Am186™CC/CH/CU Microcontrollers User’s Manual
Glossary-9
trace interrupt
The trace interrupt is the highest priority interrupt. It is a
software interrupt in that it is initiated by software, but
unlike other software interrupts, it does clears the IF
flag.
transparency
See
data transparency.
transparent mode
A mode of operation for an HDLC transmit channel that
transmits the data exactly as it appears in the FIFO.
Transparent mode does no bit stuffing, no framing with
flags, and does not support CRC. Transparent mode is
useful for transmitting raw data streams such as audio
data (for use with a codec or DSP).
transaction
The delivery of service to an endpoint. A transaction
consists of a token packet, an optional data packet, and
an optional handshake packet. Specific packets are
allowed or required based on the transaction type.
transceiver
A transmitter/receiver that can send and accept
information.
transfer
One or more bus transactions to move information
between a software client and its function.
transfer type
Determines the characteristics of the data flow between
a software client and its function. Four USB transfer
types are defined: control, interrupt, bulk, and
isochronous.
transmitter
The portion of logic for an HDLC channel or SmartDMA
channel that sends information out from the Am186CC/
CH/CU microcontrollers.
TSA
Time-slot assigner. The portion of logic in an HDLC
channel that directs data from the HDLC channel to an
external communication interface or vice versa. A TSA’s
main function is to allow the transmission and reception
of data to and from an individual HDLC by providing the
appropriate HDLC clock and clock enable signals dur-
ing its programmed time slot within an 8-KHz frame. The
Am186CC/CH/CU microcontrollers support the follow-
ing external interfaces: raw DCE and PCM Highway. In
addition, the Am186CC communications controller sup-
ports GCI.
U
UART
Universal asynchronous receiver/transmitter. A device
that provides full-duplex, bidirectional data transfer in
RS-232 format. The Am186CC/CH/CU microcontrollers
have a UART that supports speeds up to 115.2 Kbaud
and a High-Speed UART that supports speeds up to
460 Kbaud. The UARTs support full-duplex transfers in
polled, interrupt, and DMA modes.
unsynchronized transfer
A transfer of information in which the transmitter sends
data without regard for any signal or other indication
from the receiver. During an unsynchronized transfer in
DMA operations, DRQ is always asserted; and the
transfer takes place continually until the correct number
of transfers occur.
Compare to
synchronized transfer.
USB
Universal serial bus. USB is an industry standard exten-
sion to the PC architecture that provides an easy-to-use
port for connecting up to 127 peripheral devices at
transfer rates up to 12 Mbit/s. The USB specification
supports isochronous (real-time) data transfers for
voice, audio, and compressed video; bulk data transfers
for devices such as printers and terminal adapters; and
interrupt data transfers for event-driven devices such as
pointing devices and keyboards.
The USB portion of the Am186CC and Am186CU
microcontrollers supports half-duplex transfers in
polled, interrupt, and DMA modes.
USB device
A logical or physical entity that performs a function. The
actual entity described depends on the context of the
reference. At the lowest level, the term device may refer
to a single hardware component, as in a memory
device. At a higher level, it may refer to a collection of
hardware components that perform a particular func-
tion, such as a USB interface device. At an even higher
level, the term device may refer to the function per-
formed by an entity attached to the USB; for example, a
data/FAX modem device. Devices may be physical,
electrical, addressable, and logical.
USB endpoint
A uniquely identifiable portion of a USB device that is
the source or sink of information in a communication
flow between the host and device. Each endpoint is sup-
ported by a first-in-first-out buffer (FIFO). The FIFO is a
temporary storage location for the data that is passed
between the microcontroller’s CPU or memory bus and
the integrated USB peripheral controller.
See also
con-
trol endpoint
,
data endpoint
, and
interrupt endpoint
.
Summary of Contents for Am186 CC
Page 1: ...Am186 CC CH CU Microcontrollers User s Manual Order 21914B...
Page 4: ...iv Am186 CC CH CU Microcontrollers User s Manual...
Page 18: ...Table of Contents xviii Am186 CC CH CU Microcontrollers User s Manual...
Page 24: ...Introduction xxiv Am186 CC CH CU Microcontrollers User s Manual...
Page 40: ...Architectural Overview 1 16 Am186 CC CH CU Microcontrollers User s Manual...
Page 86: ...System Overview 3 36 Am186 CC CH CU Microcontrollers User s Manual...
Page 92: ...Emulator Support 4 6 Am186 CC CH CU Microcontrollers User s Manual...
Page 112: ...DRAM Controller 6 8 Am186 CC CH CU Microcontrollers User s Manual...
Page 134: ...Interrupts 7 22 Am186 CC CH CU Microcontrollers User s Manual...
Page 186: ...Programmable I O Signals 9 8 Am186 CC CH CU Microcontrollers User s Manual...
Page 200: ...Watchdog Timer 11 6 Am186 CC CH CU Microcontrollers User s Manual...
Page 232: ...Asynchronous Serial Ports UARTs 13 24 Am186 CC CH CU Microcontrollers User s Manual...
Page 242: ...Synchronous Serial Port SSI 14 10 Am186 CC CH CU Microcontrollers User s Manual...
Page 264: ...High Level Data Link Control HDLC 15 22 Am186 CC CH CU Microcontrollers User s Manual...
Page 332: ...Universal Serial Bus USB 18 34 Am186 CC CH CU Microcontrollers User s Manual...
Page 348: ...Register Summary A 16 Am186 CC CH CU Microcontrollers User s Manual...
Page 376: ...Index Index 18 Am186 CC CH CU Microcontrollers User s Manual...