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We have implement the SPI communication with PIC (16F876A) in order to send the corresponding signals to the TRF3765 (CLOCK, DATA, STROBE) but the TRF did not read the signals.
We think the signals are fine, we have checked this with an digital oscilloscope.
Someone has implemented the SPI communication in other way and can help us to do this.
We will appreciate your help.
Best regards,
Mariana.
You might consider downloading the TRF3765 GUI from ti.com. Then you would be able to compare known-good waveforms against your own waveforms by monitoring EVM testpoints. Note that the EVM communication uses USB signals routed through an FTDI device, so the SPI (4WI) signals can only be viewed after the FTDI device.
Peter,
Thank you for your answer.
Where we can find the TRF3765 GUI?
Some more question:
When we send the SPI signals is necessary supply all VCC pins?
Is necessary do something else before send the SPI signals to the TRF?
Do you have an example of a code to program a microprocessor (like PIC) which send SPI signals?
Because we would like to compare the code which we compile to the PIC with other example.
Thank you.
On ti.com, search for the TRF3765 EVM. The GUI is available on the product page under the Software heading.
Only VCC_DIG is required to access the 4WI (SPI) registers. However, it may be useful to power other supplies to monitor operation of the device.
Once power is applied to the device, it is able to receive writes to the registers. Nothing special needs to happen before the device receives commands. If the timing and sequences specified in the datasheet are observed, there are no other known requirements. Oscilloscope waveforms have been posted for reference previously in this forum at http://e2e.ti.com/support/rf__digital_radio/high_performance_rf_modulators_pll_and_vco_products/f/224/t/212323.aspx.
TI's TRF3765 GUI was developed in LabVIEW.
The best example for the TRF3765 is the programming GUI available on ti.com. The device follows the standard 4-wire interface for SPI communication. The register mapping as seen in the datasheet (4 address bits, 28 data bits) may be deemed non-standard. In general you are free to clock in the data through any means at your disposal (i.e. uP, LabVIEW, CPLD, etc.).
--Russell
Ah, I understand. I have not used the TM4C1294 for programming. It seems like it would be possible to use two 16-bit words to generate one register write. Obviously, the key is to toggle the LE at the appropriate time. Perhaps the support team for the TM4C1294 can offer some suggestions to program a 32-bit register.
--RJH