CX81801-73 Просмотр технического описания (PDF) - Conexant Systems

Номер в каталоге

Компоненты Описание

производитель

CX81801-73

SmartV.XX Modem

Conexant Systems 

5.3.2

5.4

5.4.1

CX81801-7x/8x SmartV.XX Modem Data Sheet

Receiver Character Timeout Interrupts

When the FIFO mode is enabled (FCR0 = 1) and receiver interrupt (Receiver Data

Available) is enabled (IER0 = 1), receiver character timeout interrupt operation is as

follows:

1. A Receiver character timeout interrupt code (IIR0-IIR3 = Ch) is set if at least one

received character is in the RX FIFO, the most recent received serial character was

longer than four continuous character times ago (if 2 stop bits are specified, the

second stop bit is included in this time period), and the most recent host read of the

RX FIFO was longer than four continuous character times ago.

Transmitter FIFO Interrupt Operation

Transmitter Empty Interrupt

When the FIFO mode is enabled (FCR0 = 1) and transmitter interrupt (TX Buffer Empty)

is enabled (IER0 = 1), transmitter interrupt operation is as follows:

The TX Buffer Empty interrupt code (IIR0-IIR3 = 2h) will occur when the TX Buffer is

empty; it is cleared when the TX Buffer is written to (1 to 16 characters) or the IIR is

read.

The TX Buffer Empty indications will be delayed 1 character time minus the last stop bit

time whenever the following occur: THRE = 1 and there have not been at least two bytes

at the same time in the TX FIFO Buffer since the last setting of THRE was set. The first

transmitter interrupt after setting FCR0 will be immediate.

102199B

Conexant

5-11

Share Link: