Gnss Interface; Nfc Interface - Nokia RM-824 Service Manual

RM-824; RM-825; RM-826
System Module
The BT and WLAN 2G antenna route goes through the discrete WLAN/BT RF bandpass filter and discrete RF
diplexer component. Bluetooth and WLAN 2 GHz and WLAN 5 GHz use the same antenna. Transmitting output
power level is changed according to data rate. The highest power levels are provided in 802.11b data rates.
The BT BB interface can be logically divided into a 2-line digital serial interface that supports Rx/Tx and single
wire serial bus (SSBI) for status and control. The interface between the BB and Bluetooth assumes that all
layers above the HCI are implemented in the BB, and all layers below it in the WCN3660 module.
The WLAN BB interface can be logically divided into a 4-line analog baseband interface and a 5-line digital
command and control interface. The I/Q baseband analog interface consists of 4-line analog transmission
lines shared between the Tx and Rx paths. In Tx mode, the four lines are used to connect DAC output pins to
Tx BBF input pins. In Rx mode, the four lines are used to connect Rx BBF output pins to ADC input pins.
For dual-band operation at 2.4 and 5.0 GHz, the WCN3660 device uses a 48.0 MHz clock from an external
crystal.

GNSS interface

GPS/Glonass support is built into the RTR8600 and interfaces with the MSM8960 GNSS Processor.
The 19.2 MHz reference clock of RTR8600 is also used for GPS.
The front end includes an LNA module with a SAW filter and balun filter before RTR8600. A diplexer is used
to combine GPS+GLONASS and LTE RX diversity to the same antenna (RM-825). The diplexer is not needed for
RM-824.

NFC interface

Near Field Communication (NFC) is a short-range wireless connectivity technology standard. NFC is based on
inductive-coupling, where loosely coupled inductive circuits share power and data over a distance of a few
centimeters. NFC works at 13.56 MHz frequency. It is connected to the host processor via I2C bus. The system
has also ENABLE and RESET lines from the host, and IRQ and CLK_REQ lines to the host. NFC requires VBAT and
Issue 2
Figure 36 CWS block diagram
Figure 37 GPS interface
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