Power ManagementのトピックRe: FS4500 wake up

FS4500 wake up

ydygcvjhbjkjnkn — Wed, 16 Apr 2025 07:01:35 GMT

Asking for help

Now I am using FS4500, I want to go to sleep and use 1145CAN transceiver to wake up. The INH of the transceiver is connected to IO_0 of the SBC board. Using the host computer to send the wake-up frame packet, the INH pin of the 1145CAN transceiver changes from low output to high output, and the IO_0 pin of the SBC board will also change accordingly. The question is whether I need to use the ICU driver to capture the interrupt and exit sleep or another way, or if the IO_0 pin changes accordingly, the register value will be updated automatically. Quit sleep? Asking for help

Re: FS4500 wake up

TomasVaverka — Wed, 16 Apr 2025 08:14:14 GMT

Hi,

I think that you do not need the ICU driver. Once configured properly (IO_0 connected to INH, WU_IO0_1:0 = 0b01 ), the FS4500 will autonomously wake up from sleep when IO_0 transitions (e.g. when INH goes high in response to a specific CAN frame).

BRs, Tomas

Re: FS4500 wake up

ydygcvjhbjkjnkn — Wed, 16 Apr 2025 09:00:33 GMT

谢谢你的解答，
不过我现在在将1145收发器设置为睡眠模式后，FS4500也进入LPOFF模式后，使用上位机发送CAN报文，读取到1145收发器的寄存器CW置为1，表示1145收发器检测到唤醒事件，此时1145收发器的INH引脚应该会有高低变化（因器件引脚不好测试，未测试），不过FS4500在通过SPI指令睡眠之后，仍然不能执行后续代码，我理解的也就是还未唤醒，想要请教大佬，我应该怎么做

Re: FS4500 wake up

ydygcvjhbjkjnkn — Wed, 16 Apr 2025 09:37:03 GMT

Thank you for your answer,
However, after I set the 1145 transceiver to sleep mode and FS4500 also enters LPOFF mode, I use the host computer to send CAN packets. The register CW of the 1145 transceiver is read and set to 1, indicating that the 1145 transceiver has detected the wake-up event. At this time, the INH pin of the 1145 transceiver should have a high or low change (because the device pin is not well tested, not tested), but the FS4500 can not execute the subsequent code after sleeping through the SPI command, I understand that it is not awake, want to ask the big brother, what should I do

Re: FS4500 wake up

TomasVaverka — Thu, 17 Apr 2025 07:05:17 GMT

Hi,

If CW bit is set, wake-up was successful on TJA1145 side. Try probing the INH pin with an oscilloscope or logic analyzer to confirm if it goes from low to high (~VBAT) after the wake-up event. If INH does not toggle high, FS4500 will not detect a wake source on IO_0 and will remain in LPOFF.

If INH pin behavior is ok, double check your IO_0 pin configuration as a wake-up capable input before entering LPOFF. Otherwise, FS4500 will not detect the INH signal change and will not leave LPOFF.

BRs, Tomas