Technical
Description
Sealevel Systems
ACB-II
Page
7
Technical Description
The
ACB-II
utilizes the Zilog 85230
S
erial
C
ommunications
C
ontroller
(SCC). This chip features programmable baud rate, data format, interrupt
control, and DMA control. Refer to the SCC User’s Manual, the Zilog
Datacom I/C Handbook and the ACB Developers Toolkit diskette for
details on programming the SCC chip.
Features
•
Sync/Async Communications using 85230 chip
•
DMA supports data rates greater that one million bits per second
•
Selectable port address
•
Selectable IRQ Level (3,4,5)
•
Selectable DMA Channel (1or 3)
•
RS-232 or RS-422/485 interface
•
Supports TD, RD, RTS, CTS, TXC, RXC Signals
•
Jumper options for clock source
•
Software programmable baud rate
•
Software Toolkit provided
•
Short card, DB-25 male connector
Programable Baud Rate Generator
The baud rate of the SCC is programmed under software control. The
standard oscillator supplied with the board is 7.3728 Megahertz (MHz).
Other values may be substituted to achieve a higher or different baud rate,
if required, by replacing the oscillator (U9) with a different part. Refer to
the SCC User’s Manual and the ACB Developers Toolkit diskette for baud
rate divisors and programming information.
