So i use the flexcan drivers with mailboxes under the sdk 0.8.6 with freertos on the s32k144 (engineering samples right now).
Problem:
First receiveBlocking call to can works properly, any subsequent is blocking forever/timeouting with status TIMEOUT despite there are can messages qualifiying are on the bus and received by the can core. It happens on can and canfd packages.
Mitigation in debugger:
A. Read !any! of the registers of the Flexcan peripheral between receives does allow a subsequent receive
B. Doing the RxMailbox Configuration again will allow one more package to be received (tested doing this after a timeout will result in an timeout/success/timeout cycle).
Mitigation in runtime:
use nonblocking and callback works
Environment:
CAN or CANFD with 500kbits, CPU Clock from PLL with 80MHz, Busclock with 10/20/40MHz tested, PE Clock is CPU/Sys Clock with 80MHz, but 16MHz from SOSC does also not work.
CAN PE works, as the frames are acknowledged.
Optimization is disabled.
Idea:
Cache problems might be an issue due to to rather "tricky" way to lock and unlock mailboxes and the read to the timer to unlock "(void)*base->TIMER" is cached?
Todo:
check if cache disable will help, but need info howto do it
Code:
INIT:
INT_SYS_SetPriority(CAN0_ORed_IRQn, 4);
INT_SYS_SetPriority(CAN0_Error_IRQn, 4);
INT_SYS_SetPriority(CAN0_Wake_Up_IRQn, 4);
INT_SYS_SetPriority(CAN0_ORed_0_15_MB_IRQn, 4);
INT_SYS_SetPriority(CAN0_ORed_16_31_MB_IRQn, 4);
FLEXCAN_DRV_Init(INST_CANCOM1, &canCom1_State, &canCom1_InitConfig0);
FLEXCAN_DRV_SetRxMbGlobalMask(INST_CANCOM1, FLEXCAN_MSG_ID_EXT, 0x00);
FLEXCAN_DRV_SetRxMbGlobalMask(INST_CANCOM1, FLEXCAN_MSG_ID_STD, 0x00);
Task:
flexcan_data_info_t info = {
.msg_id_type = FLEXCAN_MSG_ID_STD, /*!< Type of message ID (standard or extended)*/
.data_length = 64, /*!< Length of Data in Bytes*/
.fd_enable = true, /*!< Enable or disable FD*/
.fd_padding = 0, /*!< Set a value for padding. It will be used when the data length code (DLC)
specifies a bigger payload size than data_length to fill the MB */
.enable_brs = true, /*!< Enable bit rate switch inside a CAN FD format frame*/
.is_remote = false, /*!< Specifies if the frame is standard or remote */
};
FLEXCAN_DRV_ConfigRxMb (INST_CANCOM1, 0 , &info, 0);
flexcan_msgbuff_t msgIn;
while(1) {
status = FLEXCAN_DRV_ReceiveBlocking(INST_CANCOM1, 0 , &msgIn, 1000);
if (status == STATUS_SUCCESS) {
/* process frame */
} else {
/* reset mbx */
FLEXCAN_DRV_ConfigRxMb (INST_CANCOM1, 0 , &info, 0);
}
}
