topic Re: What it mean in MBs 1-5 in Rx FIFO structure? in S32K

What it mean in MBs 1-5 in Rx FIFO structure?

xiaobaby22 — Sat, 22 Jul 2023 05:34:58 GMT

Hello, i use the S32k118 chip. and use the Standard Can.

i'm in trouble in the program.I use CANOE to send 10 message,and set period to one 20ms and others are 100ms.But i found it may lost the message.Could you help me or offer some information?

First,i took some configuration in flexcan,like set MCR[RFEN] = 0x01,

So the Rx FIFO table:MB 0-9:

1.MBs 0~5 is used by the reception FIFO engine.in MB0，it will save the ID and data,but i see the MB1~5 is reserved.i don't what it mean.i think this area(MB1~5) is to save the message when many frame come in same time.do you agree?

2.MBs 6~9 is used to save the RX ID,so the maximum number of RX message is16. right?

Re: What it mean in MBs 1-5 in Rx FIFO structure?

Senlent — Mon, 24 Jul 2023 02:34:04 GMT

Hi@xiaobaby22

For details you need to read the datasheet and briefly answer your question as below.

Re: What it mean in MBs 1-5 in Rx FIFO structure?

xiaobaby22 — Mon, 24 Jul 2023 04:58:27 GMT

对，我确实看到MB0里面保存着一帧未读的数据。但是当FIFO中有4，5帧的时候。这个未读得数据放在哪啊？是不是放在MB1~MB5中，只是我们用户不可见啊？

Re: What it mean in MBs 1-5 in Rx FIFO structure?

Senlent — Mon, 24 Jul 2023 06:08:06 GMT

Hi@xiaobaby22

MB0~MB5既然作为了FIFO引擎使用，那么它的结构可能并不是和MB的存储结构一致，不过多余的帧肯定是存在FIFO引擎中的。