Asynchronous Serial Port
10-1
CHAPTER
10
ASYNCHRONOUS SERIAL PORTS
10.1
OVERVIEW
The Am186ES and Am188ES microcontrollers provide two independent asynchronous
serial ports. These ports provide full-duplex, bidirectional data transfer using several
industry-standard communications protocols. The serial ports may be used as sources or
destinations of DMA transfers.
The asynchronous serial ports support the following features:
n
Full-duplex operation
n
7-bit, 8-bit, or 9-bit data transfers
n
Odd, even, or no parity
n
One stop bit
n
Two lengths of break characters
n
Error detection
— Parity errors
— Framing errors
— Overrun errors
n
Hardware handshaking with the following selectable control signals:
— Clear-to-send (CTS)
— Enable-receiver-request (ENRX)
— Ready-to-send (RTS)
— Ready-to-receive (RTR)
n
DMA to and from the serial ports
n
Separate maskable interrupts for each port
n
Multidrop protocol (9-bit) support
n
Independent baud rate generators
n
Maximum baud rate of 1/16th of the CPU clock
n
Double-buffered transmit and receive
10.1.1
Serial Port Flow Control
The Am186ES and Am188ES microcontrollers provide two identical asynchronous serial
ports. Four external pins are available for each port, as shown in Table 10-1.
Summary of Contents for Am186 ES
Page 1: ...Am186 ES and Am188 ES User s Manual...
Page 4: ...iv...
Page 12: ...Table of Contents xii...
Page 22: ...Features and Performance 1 8...
Page 60: ...System Overview 3 28...
Page 84: ...Chip Select Unit 5 14...
Page 132: ...Timer Control Unit 8 8...
Page 166: ...Programmable I O Pins 11 6...
Page 184: ...Register Summary A 18...