Signals description – Compuprint 10200 Programmer Manual User Manual
Page 211
Interfaces
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According to the IEEE - P1284 Standard, the pins assume different meanings and are identified by
different names depending on the actual handshaking mode as follows:
•
Compatibility mode (Centronics)
This is the lower level mode provides an asynchronous, byte-wide forward (host-to-peripheral)
channel with data and status lines used according to their original definitions. The interfaces power
up in the compatibility Mode Idle phase.
•
Nibble Mode
This mode provides an asynchronous, reverse (peripheral-to-host) channel, under control of
the host. In this mode, peripheral device to host data bytes are sent as two sequential, four-
bit nibbles using the four peripheral-to-host status lines. These two modes cannot be active
simultaneously.
•
Byte Mode
This mode provides an asynchronous, byte-wide reverse (peripheral-to host) channel based
on eight data lines of the interface for data and the control/status lines for handshaking.
Byte mode is under host control and it cannot be simultaneously active with compatibility
mode.