Hi,
as explained previously, IO configuration register 1 (ST25R3911_REG_IO_CONF1) bit 3 has be configured in accordance with 13.56 or 27.12 MHz crystal. See ST25R3911B datasheet § 1.3.1 IO configuration register 1.
So,
- for a 27.12 MHz crystal, ST25R3911_REG_IO_CONF1 bit 3 has to be 1 which is the default reset value
- for a 13.56 MHz crystal, ST25R3911_REG_IO_CONF1 bit 3 has to be 0. In that case, an explicit st25r3911WriteRegister(ST25R3911_REG_IO_CONF1, 0x00); is needed before st25r3911OscOn() in st25r3911Initialize().
Then, Auxiliary display register (ST25R3911_REG_AUX_DISPLAY) bit 4 (osc_ok) indicates that Xtal oscillator is active and its output is stable. This is why I've suggested to add the following code at then end of st25r3911OscOn():
/* Double check that OSC_OK signal is set */
if( !st25r3911CheckReg( ST25R3911_REG_AUX_DISPLAY, ST25R3911_REG_AUX_DISPLAY_osc_ok, ST25R3911_REG_AUX_DISPLAY_osc_ok ) )
{
plateformLog("Osc not running\r\n");
}
The rational is to avoid to have to probe the crystal as the probe may affect the crystal behavior. If value of bit4 of Auxiliary display register is 0, then the crystal is not oscillating.
Also, make sure your crystal respects the recommandation from the datasheet, in particular the ESRMax (equivalent series resistance max value) is 150 Ohm.
You can as well check that the crystal has not been 90° rotated before being soldered on the PCB.
Rgds
BT
In order to give better visibility on the answered topics, please click on Accept as Solution on the reply which solved your issue or answered your question.
