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scourfield
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UART For production test

Hello Dialog,

I am using the DA14580 WLCSP.
We planned to use the JTAG port for production programming, but I notice since that the Direct Test Mode and XTAL Trimming need the UART during production..
We are using external FLASH and all GPIO pins are currently being used. So I have a couple of questions for UART for when using Direct Test and Trimming only:
1.) Can P0_5 be ok for the UART Rx along with SPI FLASH? As the cost_prod_test file will be loaded into the RAM maybe this is ok as I see some reference designs use a test point for UART on P0_5 when using FLASH.
2.) As mentioned we don't have any further spare GPIO pins. For UART Tx which would normally be paired on P0_4, can this be combined with another pin function when in Direct Test Mode and XTAL Trimming? (i.e P0_4 that uses a resistor network for hardware ID selection or other pins).

Thanks
David

TN_Dialog
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Last seen: 22 hours 26 min ago
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Joined: 2013-12-05 15:49
Hi scourfield,

Hi scourfield,

for 1) yes we woudl recomend to use P0_5 for RX muxed with SPI flash. this is what we have been doing before.

for 2) as long as the resistor network do not interfear with the UART commiunication there should not be an issue with this either.

 

Regards

TN_Dialog