rtd DM6210, Руководство пользователя

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8-4
BA + 15: Digital I/O Control (Read/Write 8-bit)
This register is used to set the digital I/O direction and enable the digital inputs to be latched. Reading
this register returns the current settings.
Bit 0 – Sets the direction of the Port 0.0 - Port 0.3 digital lines.
Bit 1 – Sets the direction of the Port 0.4 - Port 0.7 digital lines.
Bit 2 – Sets the direction of the Port 1.0 - Port 1.3 digital lines.
Bit 3 – Sets the direction of the Port 1.4 - Port 1.7 digital lines.
Bit 4 – Enables latch mode for the Port 0 input lines. When this mode is enabled, data can be strobed and
latched into Port 0 on either the rising edge or the falling edge of the strobe signal selected at BA
+ 14.
Bit 5 – Enables latch mode for the Port 1 input lines. When this mode is enabled, data can be strobed and
latched into Port 1 on either the rising edge or the falling edge of the strobe signal selected at BA
+ 14.
Bit 6 – Select Port 0 strobe polarity. This bit has no meaning if latching is disabled on Port 0.
Bit 7 – Select Port 1 strobe polarity. This bit has no meaning if latching is disabled on Port 1.
Strobing Data into Port 0 or Port 1
If you enable latch mode for either Port 0 or Port 1, data can be strobed into the respective port. This
means that data can be latched into the input latch and will remain at this value until another input strobe
signal appears even if the input data changes. The input strobe signal can be selected from 3 different sources
specified at BA + 14. Both Port 0 and Port 1 use the same strobe signal. The data can be latched on either the
positive edge or the negative edge of the strobe. This is set up by bits 6 and 7 at BA + 15. Status bits at BA + 6
can be monitored to show whether data has been latched. These status bits are cleared when the digital input
port is read.
Port 1 High Direction (P1.4 - P1.7)
0 = input
1 = output
Port 0 Latch Enable
0 = disabled
1 = enabled
Port 1 Latch Enable
0 = disabled
1 = enabled
Port 0 Strobe Polarity
0 = positive edge
1 = negative edge
' ' ' ' ' ' ' '
Port 0 Low Direction (P0.0 - P0.3)
0 = input
1 = output
Port 0 High Direction (P0.4 - P0.7)
0 = input
1 = output
Port 1 Low Direction (P1.0 - P1.3)
0 = input
1 = output
Port 1 Strobe Polarity
0 = positive edge
1 = negative edge