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LPC1549 SPI0 SSEL0 never gets low

Question asked by Sven Savic on Sep 28, 2019
Latest reply on Oct 11, 2019 by Alice_Yang

I am not sure what am I doing wrong, but ssel0 never gets pulled low. I am using lpcxpresso1549 board with arduino ethernet shield. Pins are configured in SWM as per arduino requirement.

P0.12 - MISO

P0.28 - Mosi

P0.14 - SCK

P0.27 - SSEL0

 

 

Checking PINASSIGN3 and 4, shows correct assignment. I left IOCON as default.

SPI0 is enabled, TXCTL->SEL0 = 1, rest are 0.

CFG->SPOL0 = 0; CFG->MASTER = 1; CFG->CPHA = 0; CFG->CPOL = 0; 

SYSCON->SYSAHBCLKCTRL1->SPI0 = 1

Starting spi0 write, ssel never gets low.

SPI->STAT->RXRDY = 1; TXRDY = 1; STALLED = 1; SSA = 1; ENDTRANSFER = 0; IDLE = 0;

 

If I control the ssel pin manually I get some garbage on the clock and master out (not what I would expect to get), also after burst of 8bits spi0 status go to stalled.

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