STS1TX datasheet(52/70 Pages) STMICROELECTRONICS

52 / 70 page

MCU interface

STS1TX

52/70

DocID025109 Rev 1

All interrupts are reported on a set of interrupt status registers and are individually

maskable. The interrupt status register must be cleared upon a read event from the MCU.

The status of all the interrupts is reported on the IRQ_STATUS[3:0] registers: bits are high

for the events that have generated any interrupts. The interrupts are individually maskable

using the IRQ_MASK[3:0] registers: if the mask bit related to a particular event is

programmed at 0, that event does not generate any interrupt request.

Digital inputs can be selected from the following (see GPIOx_CONF register):

Not used

TX mode indicator (to enable an external range extender)

VDD (to emulate an additional GPIO of the MCU, programmable by SPI)

GND (to emulate an additional GPIO of the MCU, programmable by SPI)

External SMPS enable signal (active high)

Device in SLEEP or STANDBY states

Device in READY state

Device in LOCK state

Device waiting for a high level of the lock-detector output signal

Device waiting for timer expiration before starting to sample the lock-detector output

signal

Device waiting for a high level of the READY2 signal from XO

Device waiting for timer expiration to allow PM block settling

Device waiting for end of VCO calibration

Device enables the full circuitry of the SYNTH block

Device waiting for a high level of the RCCAL_OK signal from the RCO calibrator

Table 31. Digital inputs

I/O selection

Input signal

1 >> TX command

Not used

TX data input for direct modulation

Table 30. Digital outputs (continued)

I/O selection

Output signal

STS1TX 데이터시트(PDF) 52 Page - STMicroelectronics