Zebra 01407-000 Manual Do Utilizador
71
Interfaces
Parallel Interface (TTP 1020)
03/03/2009
TTP 1020™/TTP 1030™ Technical Manual
P1003643-001
Table 11 • The Extensibility Byte and Allowed Values
The peripheral uses the XFlag to acknowledge that the requested mode is available. The XFlag
will always be set to one as a positive acknowledgment for all requests except for Nibble
Mode reverse channel. All 1284-compliant devices are required to support Nibble Mode for
reverse channel operation. The Extensibility Link request bit is used to provide a mechanism
for future expansion and addition of new operational modes and features.
will always be set to one as a positive acknowledgment for all requests except for Nibble
Mode reverse channel. All 1284-compliant devices are required to support Nibble Mode for
reverse channel operation. The Extensibility Link request bit is used to provide a mechanism
for future expansion and addition of new operational modes and features.
Negotiation and device ID are key features for the future ability of host platforms to determine
system configuration and to include parallel port attached peripherals in this determination.
system configuration and to include parallel port attached peripherals in this determination.
Bit
Description
Valid bit values: 8765 4321
8
Request Extensibility Link
1000 0000
7
Request EPP Mode
0100 0000
6
Request ECP Mode with RLE
0011 0000
5
Request ECP Mode without RLE
0001 0000
4
Reserved
0000 1000
3
Request device ID
Return data using Nibble Mode:
0000 0100
Return data using Byte Mode:
0000 0101
Return data using ECP Mode without RLE:
0001 0100
Return data using ECP Mode with RLE:
0011 0100
2
Reserved
0000 0010
1
Byte Mode
0000 0001
none Nibble Mode
0000 0000