ST25DV64KC datasheet(47/203 Pages) STMICROELECTRONICS

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5.4.5

Configuring GPO

GPO and interruption pulse duration can be configured by RF user or by I2C host. One or more interrupts can be

enabled at same time.

RF user can use Read Configuration and Write Configuration commands to set accordingly the GPO1 and GPO2

registers, after presenting a valid RF configuration password to open RF configuration security session.

I2C host can write GPO1 and GPO2 registers, after presenting a valid I2C password to open I2C security session.

Enabling or disabling GPO output:

•

RF user and I2C host can disable or enable GPO output at power up time by writing in GPO_EN bit 0 of

GPO1 register (if write access is granted).

•

I2C host can temporarily enable or disable GPO output at any time by toggling GPO_EN bit 0 of

GPO_CTRL_Dyn register. No password is required to write into GPO_CTRL_Dyn register.

•

Disabling GPO output by writing in GPO_EN bit (either in GPO1 or in GPO_CTRL_Dyn registers) does not

disable interruption report in IT_STS_Dyn status register.

Table 38. Enabling or disabling GPO interruptions

GPO1 bit 0:

GPO_EN

GPO_CTRL_Dyn bit 0:

GPO_EN

GPO output

GPO remains High-Z (open drain version) or is tied to ground (CMOS version).

Activated RF and I2C events are reported on GPO output.(1)

Activated RF and I2C events are reported on GPO output. (1)

1. If pull-up resistor is powered (open drain version) or VDCG is powered (CMOS version).

Interruption pulse duration configuration:

•

Interrupt pulse duration is configured by writing pulse duration value in bits 4 to 2 (IT_TIME) of GPO2

•

Pulse duration is calculated with the following equation

IT pulse duration equation:

ITpulseduration=301μs−IT_TIME×37.65μs±2μs

(1)

ST25DV04KC ST25DV16KC ST25DV64KC

GPO

DS13519 - Rev 3

page 47/203

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