FDC37B77X SMSC Corporation, FDC37B77X Datasheet - Page 99

• Manufacturer Part Number: FDC37B77X
• Description: ENHANCED SUPER I/O CONTROLLER WITH WAKE UP FEATURES
• Manufacturer: SMSC Corporation

Command/Data
ECP Mode supports two advanced features to
improve the effectiveness of the protocol for
some
implemented by allowing the transfer of normal
8 bit data or 8 bit commands.
When in the forward direction, normal data is
transferred when HostAck is high and an 8 bit
command is transferred when HostAck is low.
applications.
The
features
are
99
The most significant bit of the command
indicates whether it is a run-length count (for
compression) or a channel address.
When in the reverse direction, normal data is
transferred when PeriphAck is high and an 8 bit
command is transferred when PeriphAck is low.
The most significant bit of the command is
always zero. Reverse channel addresses are
seldom used and may not be supported in
hardware.