User`s manual

A-2 Intellio C218Turbo User's Manual
C218Turbo
Windows NT ✓
Windows 95/98 ✓
SCO UNIX/OpenServer/XENIX ✓
UNIX SVR4.2 ✓
DOS ✓
Linux 2.0.x/2.2.x ✓
✓ : Driver supported by Moxa and shipped with product
Note: MOXA FTP service is available for newest driver download
Dual-Ported RAM
There is 512 KB of dual-ported DRAM on the C218Turbo, which is used as a data
buffer and memory map device for the mother board. It is called “dual-ported”
because it is accessed by both mother board CPU and the C218Turbo on-board
CPU. Generally speaking, the memory access time is much faster than normal I/O
access.
All messages and data are transferred through this 512 KB dual-ported memory. The
buffer area appears as normal 16-bit memory to the PC AT I/O channel.
Each C218Turbo only occupies 16 KB of memory space (window) from the system
point of view. There are six possible base memory addresses you can choose from,
which are below 1 MB. Please see Chapter “Hardware Installation” for details.
UART 16550C
The UART chip, 16550C, is an intelligent asynchronous controller capable of
supporting one full duplex channel that transfers data at 921.6 Kbps simultaneously.
To increase the overall data throughput, special features such as on-chip FIFO and
on-chip hardware flow control are used to reduce the number of interrupts to the on
board CPU and to prevent any loss of valuable data.