Rainbow Electronics RF01 - Manual (Page 17)

RF01
FIFO and clear its content. Bit 0 modifies the function of pin 6 and pin 7. Pin 6 (nFFS) will become input if fe
is set to 1. If the chip is used in FIFO mode, do not allow this to be a floating input.
Reset Mode Command
bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 POR
1 1 0 1 1 0 1 0 0 0 0 0 0 0 0 dr DAOOh
Bit 0 (dr): Disables the highly sensitive RESET mode. If this bit is cleared, a 600 mV glitch in the power supply
may cause a system reset. For
more detailed description see the Reset modes section.
Status Read Command:
The read command starts with a zero, whereas all other control commands start with a one.
Therefore, after receiving the first bit of the control command the RF01 identifies it as a read command.
So as the first bit of the command is received, the receiver starts to clock out the status bits on the SDO
output as follows:
Status Register Read Sequence with FIFO Read Example
It is possible to read out the content of the FIFO after the reading of the status bits. The command can be
aborted after any read bits by rising edge of the select signal.
Note: The FIFO IT bit behaves like a status bit, but generates nIRQ pulse if active. To check whether there
is a sufficient amount of data in the FIFO, the SDO output can be tested. In extreme speed critical
applications, it can be useful to read only the first four bits (FIFO IT -LBD) to clear the FFOV, WK-UP, and
LBD bits. During the FIFO access the f
SCK
cannot be higher than f
ref
/4, where f
ref
is the crystal oscillator
frequency. If the FIFO is read in this mode the nFFS input must be connected to logic high level.
Definitions of the bits in the above timing diagram:
FIFO IT Number of the data bits in the FIFO is reached the preprogrammed limit
FFOV FIFO overflow
WK-UP Wake-up timer overflow
LBD Low battery detect, the power supply voltage is below the preprogrammed limit
FFEM FIFO is empty
DRSSI The strength of the incoming signal is above the preprogrammed limit
DQD Data Quality Detector detected a good quality signal
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