Specifications

Serial Communications (82050)
FUNCTIONAL DESCRIPTION
The ACC is functionally compatible with the industry standard
16450/8250A found in most Personal Computers. Figure 11-1
illustrates the major functional blocks of the ACC. A description of
each functional block follows.
Receive
Buffer
Register
Line
Control
Register
Divisor
Latch (LSB)
Divisor
Latch (MSB)
Line
Status
Register
Transmit
Buffer
Register
Modem
Control
Register
Modem
Status
Register
Interrupt
Enable
Register
Interrupt
Identify
Register
Data
Bus
Buffer
Baud
Generator
Read/
Write
Control
D-D0
Internal
Data Bus
Receiver
Transmitter
Modem
Control
Interrupt
Control
A0
A1
A2
EN
IORD
IOWR
RESET
RTS
CTS
DTR /RS-485 CTRL
DSR
DCD
RI
OUT2/Parallel
Port Enable
RxD
TxD
IRQ
Figure 11–1. ACC Block Diagram.
11-4