STLC2416

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GENERAL SPECIFICATION

7.1 SYSTEM CLOCK

The STLC2416 works with a single clock provided on the XIN pin. The value of this external clock should

be any integer value from 12 … 33 MHz ±20ppm (overall).

7.1.1

SLOW CLOCK

The slow clock is used by the baseband as reference clock during the low power modes. The slow clock

requires an accuracy of ±250ppm (overall).

Several options are foreseen in order to adjust the STLC2416 behaviour according to the features of the

radio used:

– If the system clock (e.g. 13MHz) is not provided at all times (power consumption saving) and no slow

clock is provided by the system, a 32 kHz crystal must be used by the STLC2416 (default mode).

– If the system clock (e.g. 13MHz) is not provided at all times (power consumption saving) and the system

provides a slow clock at 32kHz or 3.2kHz, this signal is simply connected to the STLC2416 (lpo_clk_p).

– If the system clock (e.g. 13MHz) is provided at all times, the STLC2416 generates from the reference

clock an internal 32kHz clock. This mode is not an optimized mode for power consumption.

7.2 BOOT PROCEDURE

The boot code instructions are the first that ARM7TDMI executes after a HW reset. All the internal device's

registers are set to their default value.

There are 2 types of boot:

– Flash boot.

When boot pin is set to `1` (connected to VDD), the STLC2416 boots on its flash

– UART download boot from ROM.

When boot pin is set to `0` (connected to GND), the STLC2416 boots on its internal ROM (needed to

download the new firmware in the flash). When booting on the internal ROM, the STLC2416 will monitor

the UART interface for approximately 1.4 second. If there is no request for code downloading during this

period, the ROM jumps to flash.

7.3 CLOCK DETECTION

The STLC2416 has an automatic slow clock frequency detection (32kHz, 3.2kHz or none).

7.4 MASTER RESET

When the device's reset is held active (nreset is low), uart1_txd and uart2_txd are set to input state. When

the nreset returns high, the device starts to boot.

Remark: The device should be held in active reset for minimum 20ms in order to guarantee a complete

reset of the device.

7.5 INTERRUPTS/WAKE-UP

All GPIOs can be used both as external interrupt source and as wake-up source. In addition the chip can

be woken-up by USB, uart1_rxd, uart2_rxd, int1, int2.

7.6 V1.2 detailed functionality - Extended SCO

User Perspective - Extended SCO

This function gives improved voice quality since it enables the possibility to retransmit lost or corrupted

voice packets in both directions.