home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
QRZ! Ham Radio 6
/
QRZ Ham Radio Callsign Database - Volume 6.iso
/
mac
/
files
/
finland
/
ddlcpack.lzh
/
DDLC.DOC
< prev
next >
Wrap
Text File
|
1992-08-24
|
3KB
|
104 lines
A KA9Q NOS device driver for OH1MQK's "Dual-DDLC" card
The Dual-DDLC-card ("the card") has 2 or 4 synchronous
serial channels capable of operating up to (about) 4 Mbps each.
Dual-port memory access constraints limit the speed of all
channels together to about the said 4 Mbps.
However, that should be enough for most uses :-)
The card has synchronous interfaces (see cards technical
documentation) which contains INPUTS of Rx and Tx CLOCKS, Rx and
Tx data, RTS, CTS, and a couple of general purpose signals (1 input,
1 output). (Alike any decent synchronous modem interface.)
The card is completely MEMORY MAPPED device, and does not
have any IO-space locations. It can be configured to be in any
address within the low 1MB of PC/XT/AT/AT386 memory space at incre-
ments of 16kB. The card can be configured to use 16kB or 32kB of
memory space.
The card uses an on-board SRAM as a buffer for incoming, and
outgoing packets - alike most Ethernet boards.
The card has no access-speed limitations (unlike 8530 et.al.),
and thus has no need to do fancy delays while accessing it.
Due to PC's INT-high-active nature, the card can't share
INT with another card via PC-Bus INT signal.
Usage of the ATTACH command:
attach ddlc INIT IO-BASE INT-NRO [BOARD-SIZE]
attach ddlc CHANNEL MODE LABEL MTU SPEED DUPLEX [IP-ADDR]
Where:
INIT "init" - lowercase special label.
Indicates board definition statement. Must be
done before the actual channel attach is done.
IO-BASE Base address of the D-DDLC-board. 20-bit
hex address in the form of HHHHH.
For example: A0000
INT-NRO INT-vector number of the board.
* NR-OF-CHIPS 1 or 2
Number of equiped chips on this board.
If 1, then it must be for channels 0 and 1.
* BOARD-SIZE "16"/"32"/"16kB"/"32kB"
Tells the size of the card (of its on-board
memory size) -- comes equiped always with
32kB, but upper half can be discarded, and
address granularity stepped down to 16kB.
( Params marked with `*' are automatically figured out from the board )
The "attach init" -command must be used before the card
can get attachements of actual channels.
In the source files (ddlc.h) is definition of maximum of two
DDLC cards (DDLCMAX), but as that is up to 8 interfaces,
it should be enough...
CHANNEL 0..7
Number of channel to be attached.
0..3 on the first card, 4..7 on the second.
(And so on, if DDLCMAX is increased.)
If the card has only 1 chip, only the first
two channels of that card are usable.
MODE "ax25" or "raw" (alias "hdlc")
Lower-case special labels.
AX.25 mode and bare HDLC-encapsulation (wire
line) supported.
LABEL "dd0"
As usual, label for the channel.
MTU 1500 (or whatever)
As usual, MTU size.
SPEED 56000/9600/1200/250000/2000000/...
Informative text for status display.
interface speed IS NOT configurable
by the software. Both clocks come
from the modem.
DUPLEX "full" / "half" / "fullduplex" / "halfduplex" /
(Recognize by the first character; f or h)
Tells wether or not the channel has a full
or a half-duplex radio-/wire-modem.
IP-ADDR 44.109.04.20
Optionally define interface IP number(s).
Defaults to global Ip_addr.
Quite normal form of attach-command.