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IA8251
Advanced Information Sheet
Programmable Communication Interface
The IA8251 provides an interface between a microprocessor and a serial communications channel.
The IA8251 receives and transmits data in a variety of configurations including 7- or 8-bit data
words, with odd, even , or no parity, and 1 or 2 stop bits. The transmitter and receiver can be
designed for synchronous or asynchronous operation.
A block diagram is shown in Figure 1.
Functional Block Diagram
Figure 1
INTERNAL DATA
BUS
D7:D0
GROUP A
PORT A
(8)
DATA BUS
BUFFER
TXD
RESET
CLK
READ/WRITE
CONTROL
LOGIC
CD_n
TXRDY
RD_n
GROUP A
PORT C
TXEMPTY
WR_n
UPPER (4)
TXC_n
CS_n
DSR_n
DTR_n
CTS_n
GROUP B
PORT C
LOWER
(4)
MODEM
CONTROL
RXD
RTS_n
RXRDY
GROUP B
PORT B
(8)
RXC_n
SYNDET_BD
Copyright ã 1999, InnovASIC Inc.
Customer Specific IC Solutions
INNOVASIC [ INNOVASIC, INC ]
