Tool/software:
Hey team,
I'm using a ADS127L18EVM and wanted to interface with our FPGA based system. Currently we haven't started interfacing with the FPGA and just started testing the SPI register configurations read and write commands in the EVM. We are using an LPC55s69 microcontroller from NXP which is capable of operating at 1.8V logic configured as SPI Master. As per the datasheet I have done the following connections.
| Pin | Connection |
| MODE | Shorted to IOVDD1.8V |
| /CS | CS in LPC55s69 uC |
| SCLK | SCK in LPC55s69 uC |
| SDI | MOSI in LPC55s69 uC |
| SDO | MISO in LPC55s69 uC |
| GND | GND |
The SPI mode is set to CPOL = 0, CPHA = 1. SPI SCLK is set to 12MHz.
Currently I'm trying to read the DEVICE_ID register for which I'm sending the 2 bytes command - < 0x00 0x00 >.. But the SDO is always held HIGH. I tried writing and reading from other registers which also failed. What am I doing wrong. Any help is appreciated.
Note : The EVM otherwise works properly. I have verified ADC sampling and register configuration using the GUI and the PHI adapter provided with the kit. Just that the SPI header pins are not working as intended when interfaced with an external device.
