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Application Note
AN_289 FT51A Programming Guide
Version 1.0
Document Reference No.: FT_000962 Clearance No.: FTDI# 483
81
Copyright © 2015 Future Technology Devices International Limited
2.10.6.2
AIO_GLOBAL_PORT_SELECT_0_7
Bit
Position
Bit Field Name
Type
Reset
Description
7
aio_port_7_active
R/W
0
Write 1 to include Port in Global List
6
aio_port_6_active
R/W
0
Write 1 to include Port in Global List
5
aio_port_5_active
R/W
0
Write 1 to include Port in Global List
4
aio_port_4_active
R/W
0
Write 1 to include Port in Global List
3
aio_port_3_active
R/W
0
Write 1 to include Port in Global List
2
aio_port_2_active
R/W
0
Write 1 to include Port in Global List
1
aio_port_1_active
R/W
0
Write 1 to include Port in Global List
0
aio_port_0_active
R/W
0
Write 1 to include Port in Global List
Table 2.103 AIO Global Mode Select 0-7 Register
2.10.6.3
AIO_GLOBAL_PORT_SELECT_8_15
Bit
Position
Bit Field Name
Type
Reset
Description
7
aio_port_15_active
R/W
0
Write 1 to include Port in Global List
6
aio_port_14_active
R/W
0
Write 1 to include Port in Global List
5
aio_port_13_active
R/W
0
Write 1 to include Port in Global List
4
aio_port_12_active
R/W
0
Write 1 to include Port in Global List
3
aio_port_11_active
R/W
0
Write 1 to include Port in Global List
2
aio_port_10_active
R/W
0
Write 1 to include Port in Global List
1
aio_port_9_active
R/W
0
Write 1 to include Port in Global List
0
aio_port_8_active
R/W
0
Write 1 to include Port in Global List
Table 2.104 AIO Global Mode Select 8-15 Register
Global mode limitations
Physically there are only four DACs on the device, shared amongst all available AIO pads (see
section 2.10.2 for more detail).
This creates a limitation in Global mode and there is a potential for drift to be seen on the output if
more than two ports sharing a DAC are used in Global mode.
Therefore, we recommend that Global mode ports are spread over multiple DACs. Table 2.105
describes the recommended Global port usage.