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- 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.
-