5282 problem with QSPI CLK

[Mikeeulkeul]

Hi all,

I use the QSPI of the MCF5282 and I've a problem to generate the clock.

I'm need to communicate with 4 CAN, and they need a low state for start a convertion on the Chip select

I was inspired of a source code of different solution on your forum.

Thanks for your help in advance.

/* Enable QSPI Pins Primary Functions */

 MCF5282_GPIO_PQSPAR = 0x7F;

/* set up delay from chip select to first edge of QSPI clock */ 
 MCF5282_QSPI_QMR=0xB302;
 MCF5282_QSPI_QDLYR=0x0000; 
 MCF5282_QSPI_QIR=0xD00F;
 MCF5282_QSPI_QIR |= MCF5282_QSPI_QIR_SPIF;  /* Make sure SPIF is cleared */

/* set queue pointer to the first command RAM entry */  
 MCF5282_QSPI_QAR=0x0020; 

/* command entry for transfer to QSPI_CS0 */
 MCF5282_QSPI_QDR=0x7E00; 
 MCF5282_QSPI_QDR=0x7E00;
 MCF5282_QSPI_QDR=0x7D00;
 MCF5282_QSPI_QDR=0x7D00;
 MCF5282_QSPI_QDR=0x7B00;
 MCF5282_QSPI_QDR=0x7B00;
 MCF5282_QSPI_QDR=0x7700;
 MCF5282_QSPI_QDR=0x7700;

/* set queue pointer to the first data RAM entry */
  MCF5282_QSPI_QAR = 0x0000; 

/* data RAM entry for transfer to QSPI_CS0 */
 MCF5282_QSPI_QDR=0xFFF;
 MCF5282_QSPI_QDR=0xFFF;
 MCF5282_QSPI_QDR=0xFFF;
 MCF5282_QSPI_QDR=0xFFF;
 MCF5282_QSPI_QDR=0xFFF;
 MCF5282_QSPI_QDR=0xFFF;
 MCF5282_QSPI_QDR=0xFFF;
 MCF5282_QSPI_QDR=0xFFF;

/* set up wrap register for 8 12-bit transfers */
 MCF5282_QSPI_QWR=0x0F00; 

/*start the transfer */
 MCF5282_QSPI_QDLYR |= MCF5282_QSPI_QDLYR_SPE;

while(!(MCF5282_QSPI_QIR & MCF5282_QSPI_QIR_SPIF)){} // Wait till transfers are complete

MCF5282_QSPI_QAR=0x0010;     //Receive RAM selected
DATA = MCF5282_QSPI_QDR; 

---

[Pai]

Hi, In QWR register, set bit CSIV to 1 if you need chip select as active low; also set correctly the length of the queue: you want 8 transfers and set instead ENDQP to 'F' (16 transfers). Regards, yoan

[Mikeeulkeul]

Ok, thanks yoan.

But then I look my QSPI_CLK output, I don't see the QSPI Clock.

I don't know if my clock is correctly generated, but I see the QSPI_CLK with an oscilloscope I've a constant signal.

Regards.

[GUNNM]

YOU must set  your pin in input or in output as this register:

MCF_GPIO_DDRQS = (0
            | MCF_GPIO_DDRQS_DDRQS0
            | MCF_GPIO_DDRQS_DDRQS3
            | MCF_GPIO_DDRQS_DDRQS2);

I have a coldfire 52233 but i think that your register is the same.