Glossary
Am186™CC/CH/CU Microcontrollers User’s Manual
Glossary-7
pin
Refers to a physical wire on a chip which is available
externally.
Compare to
signal.
pinstrap
A pinstrap is used to enable or disable features based
on the state of the pin during an external reset. The pin-
strap must be held in its desired state for at least
4.5 clock cycles after the deassertion of the RES signal.
Note that the pinstraps are sampled in an external reset
only (when the RES signal is asserted) not during an
internal watchdog-timer generated reset.
PIO
Programmable input/output. Physical pins on the
Am186CC communications controller that can be used
for any purpose the system designer requires. The sig-
nal on a PIO pin can be sampled through a register and
can be driven High or Low by setting or clearing the
associated bit in the appropriate register.
pipe
A logical abstraction representing the association
between an endpoint on a USB device and software on
the host. A pipe has several attributes; for example, a
pipe may transfer data as streams (stream pipe) or mes-
sages (message pipe).
polled mode
One of three modes supported by the Am186CC com-
munications controller for serial communications. In
polled mode, software reads a status register in a loop,
and reads received data or transmits data depending on
the status register indicator bits.
Compare to
interrupt
mode
and
DMA mode.
port
Point of access to or from a system or circuit. For USB,
the point where a USB device is attached.
POTS
Plain old telephone service.
power-on reset
See
external reset.
PPP
Point to point protocol.
PRI
Primary rate interface.
programmable priority
Each interrupt channel has eight levels of programma-
ble priority that are set in the channel’s control register.
Programmable priority determines which interrupt to
service when two interrupts are requested at the same
time. An interrupt service routine is interrupted by
another interrupt request of equal or higher programma-
ble priority, as long as the Interrupt-enable Flag (IF) in
the Processor Status Flags (FLAGS) register is set. For
more information about setting the FLAGS register, see
the
Am186™CC/CH/CU Microcontrollers Register Set
Manual
, order #21916. If the programmable priority lev-
els are equal, the overall priority number is used.
PWD
Pulse width demodulation.
R
raw DCE
One of the external interfaces supported by the
Am186CC communications controller HDLC channels.
Raw DCE is a synchronous serial bus generally used in
modem and other high-speed serial applications. Raw
DCE runs at up to 10 Mbit/s. The Am186CC communi-
cations controller implementation requires transmit
(TCLK) and receive (RCLK) clock inputs, and has
receive data (RXD), transmit data (TXD), and the Clear-
To-Send (CTS) and Ready-To-Receive (RTR) flow con-
trol signals.
receiver
The portion of logic for an HDLC channel, SmartDMA
channel, or UART that processes information coming
into the Am186CC communications controller.
reset
See
external reset
,
internal reset
, and
system reset.
ring buffer
See
circular buffer.
router
The part of a communications network that receives
transmissions and forwards them to their destinations
using the shortest route available. Data may travel
through multiple routers on the way to their destination.
RTR
Ready-to-receive.
See
CTS/RTR.
RTS
Ready-to-send.
S
SCIT
Special circuit interface for terminals.
SDLC
Synchronous data link control. A data transmission pro-
tocol used by networks using Systems Network
Architecture (a communications format, advanced by
IBM, used on local-area networks to allow multiple sys-
tems access to centralized data). SDLC defines the
format used to transmit the data traveling over network
lines.
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...