NRF9E5 Datasheet, PDF (7/104 Pages) List of Unclassifed Manufacturers – 433/868/915MHz RF Transceiver with Embedded 8051 Compatible Microcontroller and 4 Input, 10 Bit ADC

PRODUCT SPECIFICATION
nRF9 E5 Single Chip Transceiver with Embedded Microcontroller and ADC
1.5 Power Management
The nRF9E5 can be placed into several low power modes under program control, and
also the ADC and RF subsystems can be turned on or off under program control. The
CPU will stop, but all RAM’s and registers maintain their values. The watchdog, RTC
(Real Time Clock) wakeup timer and the GPIO wakeup function are always active
during power down. The current consumption is typically 2.5µA when running with the
crystal oscillator off.
The device can exit the power down modes by an external pin, an event on any of the P0
GPIO pins, by the wakeup timer if enabled or by a watchdog reset.
1.6 LF Clock, RTC Wakeup Timer, GPIO Wakeup and Watchdog
The nRF9E5 contains an internal low frequency clock CKLF that is always on. When
the crystal oscillator clocks the circuit, the CKLF is a 4kHz clock derived from the
crystal oscillator. When no crystal oscillator clock is available, the CKLF is a low power
RC oscillator that cannot be disabled, so it will run continuously as long as VDD =
1.8V. The RTC Wakeup timer, the GPIO wakeup and watchdog all run on the CKLF to
ensure these vital functions will work during all power down modes.
RTC Wakeup timer is a 24 bit programmable down counter and the Watchdog is a 16 bit
programmable down counter. The resolution of the watchdog and wakeup timer is
programmable (with prescaler TICK_DV) from approximately 300µs to approximately
80ms. By default the resolution is 1ms. The wakeup timer can be started and stopped by
user software. The watchdog is disabled after a reset, but if activated it cannot be
disabled again, except by another reset. An RTC Wakeup timer timeout also provides a
programmable pulse (GTIMER) that can be an output on a GPIO pin.
The GPIO wakeup function lets the software enable wakeup on one or more pins from
the P0 GPIO port. The edge sensitivity (rising, falling or both) and de-bouncing filter is
individually programmable for each pin.
1.7 XTAL Oscillator
The microcontroller, AD converter and transceiver run on the same crystal oscillator
generated clock. A range of crystals frequencies from 4 to 20 MHz may be utilized. For
details, please see chapter 7.1 on page 17. The oscillator may be started and stopped as
requested by software.
Main office: Nordic Semiconductor ASA - Vestre Rosten 81, N-7075 Tiller, Norway -Phone [phone] - Fax [phone]
Revision: 1.1
Page 7 of 104
June 2004