Tally Genicom T5023+ User Manual
Page 392
Description of the physical interface
Appendix
382
T5023/5023+ - Programming Guide
XFlag/Select
(Printer driven)
Compatibility Mode:
Set ’high’ to indicate that the printer is on-line.
ECP Mode:
Used by the printer to reply to the requested
extensibility byte sent by the host during the
negotiation phase.
HostAck/nAutoFd
(Host driven)
Compatibility Mode:
The interpretation of this signal varies from
printer to printer. Set ’low’ by host to put some
printers into auto-line feed mode.
ECP Mode:
The host drives this signal for flow control in the
reverse direction. It is used in an interlocked
handshake with PeriphClk.
HostAck also provides a ninth data bit used to
determine whether command or data
information is present on the data signals in the
forward direction.
Peripherial Logic High
(Printer driven)
Set ’high’ to indicate that all other signals
sourced by the printer are in a valid state.
nReverseRequest / nInit
Compatibility Mode:
Pulsed ’low’ to reset the interface and force a
return to Compatibility Mode idle phase.
ECP Mode:
This signal is driven ’low’ to place the channel in
the reverse direction.