AvaLAN Wireless AW900mSPI-10 - Manual (Page 9)

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AW900mSPI User’s Manual
TX_ACT will be set for 32ms when data is queued up for transmission.
RFQ5..0: Indicates the quality of the RF link. The lowest quality is only b0 set, the
highest quality is reached when b5 is set.
DIPs:
A bit that is set in this byte indicates that the corresponding DIP switch is on.
Byte3 b7 b6 b5 b4 b3 b2 b1 b0
DCH5 DCH4 DCH3 DCH2 DCH1 DCH0 MODE -
DCH5..0: Used to set the radio into manual channel mode and use the channel indi-
cated. If DCH5..0 are all clear then the radio will be in automatic mode.
MODE: When set the unit is in troubleshooting mode, when clear the unit is in
normal operation.
SPI1 – Command Interface
SPI1 is a slave mode SPI, meaning SCK is supplied by an external source. This SPI
is used to configure the module, read status information, issue firmware upgrades
and transfer data.
The first byte on the MOSI line after the /CS_BB line goes low is the Command Byte.
This byte tells the XC1220 what command is to be executed.
Command Byte:
b7 b6 b5 b4 b3 b2 b1 b0
get/set - - - CMD3 CMD2 CMD1 CMD0
get/set: When set this bit indicates that information will be sent to the XC1220 on
MOSI1 and MISO1 will be high impedance. When clear a get transaction will take
place and information will be sent from the XC1220 on MISO1.
After the command byte is issued the master microcontroller must delay for at least
4 µs to allow the XC1220 enough time to prepare for the transaction.
When a transaction is complete and the /CS_BB line is high, the master micro-
controller must delay for at least 6 µs to allow the XC1220 to finish processing the
transaction.
CMD3..1: These bits are used to tell the XC1220 what command is to be executed.