Filter
Top Products
FENIX IMVICO
TK14 OPERATION MANUAL
28/65
3.7.5- Flow diagram of the error detection for the parallel port
The TK14 meets the IEEE-1284 standard, in the nibble mode variant.
Fig.3.11-
Nibble mode phase transitions.
NOTES:
(1) The circles represent the IEEE1284 phases.
(2) This diagram can not be considered as the true state diagram.
(3)
The host system can request the negotiation phase at any time, but the TK14 will only return a
status byte if the host system has send the DEL EOT command previously.
(4) If the printer control of the host system does not have enabled or implemented the nibble mode
according to the IEEE-1284 interface, only the compatibility mode will make communication possible.
In this case, the error signaling is reduced to the information provided by the PError and nFault pins.
END
HOST SYSTEM
END request
Compatibility mode
HOST
SYSTEM.
Forward idle
PERIPHERAL
Data transfer
Host system
Data transfer
HOST SYSTEM requires
reverse transfer
Host system
busy.
Data
available
Host system
busy
Data not
available
Negotiation
PERIPHERAL has
data to send
PERIPHERAL
does not have
data to send
Host system does
not receive data
byte.
Peripheral does
not have more
data to send
Host system
requires
data byte
PERIPHERAL
Busy,ACK,PE,/ERR
Interface
returns to
compatibility
mode
DEL EOT command not
previously sent
DEL EOT command
send previously
Negotiation
error
Reverse data
transfer