RXC101 Datasheet, PDF (15/33 Pages) RF Monolithics, Inc – Multi-channel High data rate Programmable

Wake-Up Mode
The RXC101 has an internal wake-up timer that has very low current consumption (1.5uA typical) and
may be programmed from 1msec to several days. A calibration is performed to the crystal at startup and
every 30 sec thereafter, even if in sleep mode. If the oscillator circuit is disabled the calibration circuit will
turn it on briefly to perform a calibration to maintain accurate timing and return to sleep.
The RXC101 also incorporates other power saving modes aside from the wake-up timer. Return to active
mode may be initiated from several external events:
• Logic ‘0’ applied to nINT pin (16)
• Low Supply Voltage Detect
• FIFO Fill
• SPI request
If any of these wake-up events occur, including the wake-up timer, the RXC101 generates an external
interrupt which may be used as a wake-up signal to a host processor. The source of the interrupt may be
read out from the Status Register over the SPI bus.
Low Battery Detect
The integrated low battery detector monitors the voltage supply against a preprogrammed value and
generates an interrupt when the supply voltage falls below the programmed value. The detector circuit
has 50mV of hysteresis built in.
SPI Interface
The RXC101 is equipped with a standard SPI bus that is compatible to most any SPI device. All
functions and status of the chip are accessible through the SPI bus. Typical SPI devices are configured
for byte write operations. The TRC101 uses word writes so the nCS pin should be pulled low for 16 bits.
nCS
Figure 6. SPI Interface Timing
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