Hi.
I try to implement AFE4490 chip into developed multi-functional medical diagnostic device and have the serial communication read operation problem.
AFE4490 registers write operations executed successfully. LEDs timing, LEDs current, ADC_RDY pulses etc. - all operates in accordance with the data written into these registers. But when trying to read, SPISOMI pin always stay in low state. My reading sequence:
- Set SPI READ bit (bit D0 of CONTROL0 register);
- Drive SPISTE pin low;
- Transmit a desired register address (8 bits, MSB first) with 8 SCLK pulses;
- Produce 24 more SCLK pulses.
- Drive SPISTE pin high.
If set DIGOUT_TRISTATE bit (bit D10 of CONTROL0 register), SPISOMI pin really goes into high impedance state.
Is there any explanation for this phenomenon?
Best regards,
Sergay.
