LIN module on MPC5777M EVM board ?

anishchoudhary · ‎02-16-2018

Hi,

I am working for LIN module with MPC5777M EVM board. For that I am able to transmitting data from master side and that data i am able to see the data on oscilloscope also.Then I configure the receiver on same MPC5777M EVM board but I am not able to get the frame itself in receiver or slave side. So please make me sure, can we establish communication over the LIN bus that have master and slave on same board ? How it will possible to make communication (transmitting and receiving both) on single wire If we can establish the communication over the LIN bus, which have master and slave on same board ?

PetrS · ‎02-26-2018

Hi,

As only single LIN transceiver is available on the EVB, LINFlex modules can be connected together before this transceiver in the way TX pins together and RX pins together. TX pins must be configured as open drain and use a pullup resistor (or internal weak pullup).

LINFlex_1 is connected to EVB's transceiver via pins PE6/PE7, assuming J16/J17 jumpers are fitted.

You can configure LINFlex_0 pins for example on PA12/PA13.

Then for SIUL setting

    /* Configure pad PA12 for LIN0TX */
    SIUL2.MSCR_IO[12].B.SSS = 2;    /* Pad PA12: Source signal is LIN0_TXD */
    SIUL2.MSCR_IO[12].B.ODC = 1;    /* Pad PA12: open-drain Output */
    SIUL2.MSCR_IO[12].B.OERC = 3;    /* Pad PA12: Maximum slew rate */
    SIUL2.MSCR_IO[12].B.WPUE = 1;
    /* Configure pad PA13 for LIN0RX */
    SIUL2.MSCR_IO[13].B.IBE = 1;    /* Pad PA13: Enable pad for input - LIN0_RXD */
    SIUL2.MSCR_IO[848].B.SSS = 1;   /* LIN0_RXD: connected to pad PA13 */

    /* Configure pad PE7 for LIN1TX */
    SIUL2.MSCR_IO[71].B.SSS = 2;    /* Pad PE7: Source signal is LIN1_TXD */
    SIUL2.MSCR_IO[71].B.ODC = 1;    /* Pad PE7: open-drain Output */
    SIUL2.MSCR_IO[71].B.OERC = 3;    /* Pad PE7: Maximum slew rate */
    SIUL2.MSCR_IO[71].B.WPUE = 1;
    /* Configure pad PE6 for LIN1RX */
    SIUL2.MSCR_IO[70].B.IBE = 1;    /* Pad PE6: Enable pad for input - LIN1_RXD */
    SIUL2.MSCR_IO[849].B.SSS = 1;   /* LIN1_RXD: connected to pad PE6 */

the EVB connection will be

P8.13 to P12.8 TX pins
P8.14 to P12.7 RX pins

Connect LINFlexD_1 to LIN transceiver on Motherboard
J17 - LIN_TX ON
J16 - LIN_RX ON
J15 - LIN_EN ON
P3 1-2 ON ... VSUP to 12V

Hope it helps.

BR, Petr