User Manual

B&B Electronics, Inc. Airborne WLNN DP550 Family Databook
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7.4 SPI Modes
The Airborne device supports the following four SPI modes. These are selectable
through the command line or web interfaces. The default mode is zero (0).
Table 15 - SPI Modes
SPI Mode Clock Idle Clocking Edge
0 Low High-Low (trailing edge)
1 Low Low-High (leading edge)
2 High Low-High (trailing edge)
3 High High-Low (leading edge)
7.5 SPI Commands
The following commands are available for use in the CMD message header.

Unused parameters should be set to zero.
Table 16 - SPI Command Description
Command
(Hex)
Name Description
0x00 NOP
The NOP command does nothing.
It is intended to be used when the host wants to simply retrieve
the RX Message Header without any other operation.
PARM1 and PARM2 are unused for this command and should
be set to zero.
0x04 BREAK
The BREAK command will issue a break sequence to the
module.
It is analogous to the BREAK signal on a common UART. Use
this command to issue a BREAK if the esc-mode-serial brk
setting is configured in the module.
PARM1 and PARM2 are unused for this command and should
be set to zero.
0x08 TXINTCLR
The TXINTCLR command will clear the TX interrupt.
Use this command when the module is issuing a TX interrupt
but the host has no more data to send. This is analogous to the
reset TX interrupt command on a common UART. The result of
this command is that the TX interrupt is cleared even though the
host is not writing more data to the module.
PARM1 and PARM2 are unused for this command and should
be set to zero.