DM336P

V.34 Integrated Data/ Fax/Voice/Speakerphone Modem Device Set

18

Final

Version: DM336P-DS-F02

August 15, 2000

There are two other special considerations for

software protocol. During an iteration, it is possible

that the 55H and AAH combination is never detected.

It is also possible that the checksum does not match.

If either of these cases occurs on the first iteration, it

must be assumed that the READ_DATA port is in

conflict. If a conflict is detected, then the

READ_DATA port will be relocated. The above

process is repeated until a non-conflicting location for

the READ_DATA port is found. The entire range

between 203H and 3FFH is available; however, in

practice, it is expected that only a few locations will be

tried before software determines that no Plug and

Play cards are present.

During subsequent iterations, the occurrence of either

of these two special cases should be interpreted as

the absence of any further Plug and Play cards (i.e.

the last card was found in the previous iteration). This

terminates the isolation protocol.

Note: The software must delay 1 msec prior to

starting the first pair of isolation reads, and wait

250 msec between each sub-sequence pair of

isolation reads. This delay gives the ISA card

time to access information from very slow

storage devices.

(8) Plug and Play Isolation Sequence

The Plug and Play isolation sequence is divided into four states: Wait for Key, Sleep, Isolation, and Configuration.

The state transitions for the Plug and Play ISA card are shown below:

POWER UP

RETDRV OR

RESET COMMAND

WAIT FOR KEY

STATE

ACTIVE COMMANDS

NO ACTIVE

COMMANDS

SLEEP

STATE

ACTIVE COMMANDS

RESET

RESET CSN

WAIT FOR KEY

WAKE(CSN)

ISOLATION

STATE

ACTIVE COMMANDS

RESET

RESET CSN

WAIT FOR KEY

SET RD_DATA PORT

SERIAL ISOLATION

WAKE(CSN)

SET CSN

CONFIG

STATE

ACTIVE COMMANDS

RESET

RESET CSN

WAIT FOR KEY

WAKE(CSN)

RESOURCE DATA

STATUS

LOGICAL DIVICE

I/O RANGE CHECK

ACTIVATE

CONFIGURATION REGISTERS

SET CSN

WAKE=0 & CSN=0

WAKE<>CSN

WAKE<>0 & WAKE=CSN

LOSE SERIAL ISOLATION OR

WAKE<>CSN

Note: 1. CSN = Card Select Number.

2. RSTDRV causes a state transition from the current state to Wait for Key and sets all CSNs to zero.

3. The Wait for Key command causes a state transition from the current state to Wait for Key.

4. The Reset CSN commands include PnP Reset CSN and DM Reset CSN commands.

The former sets all ISA PnP cards CSNs to zero, while the latter only sets DM6383 PnP cards

CSNs to zero. command will cause a state transition.

Plug and Play ISA Card State Transitions