topic Re: MC33774 WAKE UP in High Performance Analog Front End Interfaces

MC33774 WAKE UP

Embedded_novice — Wed, 20 May 2026 02:39:30 GMT

HI.

Currently, I am using the S32K310, MC33665A, and MC33774 chips to perform voltage acquisition. At present, my MC33665A is operating normally, and the power supply and circuit of MC33774 are also normal. However, when I send a wakeup frame through MC33665A to wake up MC33774, neither of the two AFEs in the bus chain cannot be awakened (this is determined by measuring whether the VDDC voltage can reach 5V). My current wakeup method is to send one frame of the wakeup frame and then delay for at least 10ms before sending another frame of the wakeup frame. What could be the possible reasons for the inability to wake up normally?

Another issue is that after sending the wakeup command, MC33774 did not wake up. However, when I sent a single voltage acquisition instruction, the first MC33774 was awakened, and it responded with the correct voltage value in the DADD=0 state. Is this reasonable?

wakeup frameAFE_1 responds with data in the DADD=0 stateMC33774 initialization process

Re: MC33774 WAKE UP

guoweisun — Thu, 21 May 2026 05:15:50 GMT

可以尝试：

唤醒第一个 33774 → 给第一个 33774 写入 DADD → 唤醒第二个 33774 → 给第二个 33774 写入 DADD→唤醒第 n 个33774 →给第 n 个 33774 写入 DADD。流程图如下所示：

Re: MC33774 WAKE UP

Embedded_novice — Thu, 21 May 2026 06:31:55 GMT

HI.

我尝试了这种方式，但是这种枚举方式下我的AFE1被枚举为了DADD=2，相当于我发送的枚举AFE1为DADD=1的报文被忽略或者被当成了唤醒帧。唤醒帧和枚举帧的时间间隔设置了10ms，应该满足手册中的2.4ms。请问是不是我的唤醒帧发送格式错误？