Architectural Overview
Am186™CC/CH/CU Microcontrollers User’s Manual
1-9
1.4.2.5
Asynchronous Serial Ports (Chapter 13)
The Am186CC/CH/CU microcontrollers each have two asynchronous serial ports that
provide full-duplex, bidirectional data transfer with speeds up to 460 Kbaud. One port is a
high-speed UART with transmit and receive FIFOs, special character matching, and
automatic baud rate detection, suitable for implementation of a Hayes-compatible modem
interface to a host PC. There is also a lower speed UART, which typically is used for a low
baud rate system configuration port or debug port. Each of these UARTs can derive its
baud rate from the CPU clock or from a separate baud rate generator clock input. Both
UARTs support 7-, 8-, or 9-bit data transfers; address bit generation and detection in 7- or
8-bit frames; one or two stop bits; even, odd, or no parity; break generation and detection;
hardware flow control; and DMA to and from the serial ports using the general-purpose
DMA channels (see “General-Purpose DMA Channels (Chapter 8)” on page 1-10).
1.4.2.6
Synchronous Serial Port (Chapter 14)
The Am186CC/CH/CU microcontrollers each include one SSI port, which provides a half-
duplex, bidirectional communications interface between the microcontroller and other
system components. Typical applications use this interface to monitor the status of other
system devices and to configure these devices under software control. In a communications
application, these devices could be system components such as audio coder-decoders
(codecs), line interface units, and transceivers. The SSI supports data transfer speeds of
up to 25 Mbit/s with a 50-MHz CPU clock.
The SSI port operates as an interface master with the other attached devices acting as
slave devices. Using this protocol, the microcontroller sends a command byte to the
attached device, and then follows that byte with either a read or write of a byte of data.
The SSI port consists of three I/O pins: an enable (SDEN), a clock (SCLK), and a
bidirectional data pin (SDATA). SDEN can be used directly as an enable for a single attached
device. When more than one device requires control through the SSI, use PIOs to provide
enable pins for those devices.
The SSI port is, in general, software compatible with the Am186EM SSI port. Some
additional features have been added to the Am186CC/CH/CU microcontrollers’ SSI
implementation. In addition, the microcontroller can select the polarity of the SCLK and
SDEN pins, as well as the shift order of bits on the SDATA pin (least-significant-bit first
versus most-significant-bit first). The SSI port also offers a programmable clock divisor
(dividing the clock from 2 to 256 in power of 2 increments), a bidirectional transmit/receive
shift register, and direct connection to AMD Subscriber Line Audio-processing Circuit
(SLAC™) devices.
1.4.3
System Peripherals
The Am186CC/CH/CU microcontrollers provide several additional system peripherals to
simplify incorporation of the microcontroller into an embedded application.
1.4.3.1
Interrupt Controller (Chapter 7)
The Am186CC/CH/CU microcontrollers each feature an interrupt controller, which arranges
up to 36 maskable interrupt requests by priority and presents them one at a time to the CPU.
The interrupt controller supports the maskable interrupt sources through the use of 15
channels. To make this possible, most interrupt channels support multiple interrupt sources.
These channels are programmable to support the external interrupt pins or various
peripheral devices that can be configured to generate interrupts. The maskable interrupt
sources include 17 external sources plus a number of internal sources.
The Am186CC microcontroller has 19 internal maskable interrupt sources.
CC
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...