1. ADM1276 CML_Fault issue

2. Customer use ADM1276 to do the POWER_CYCLE command to do loop test, meet CML_FAULT error. The steps of experiment show as below and all of results we find out within 3 cases. (a) enable alert pin via set CML_ERROR_EN1 of ALERT_1_CONFIGURATION_REGISTER to 1 (b) In first console, keep issue STATUS_WORD command to read data recursively. (c) In second console, issue POWER_CYCLE command recursively. (d) At digital oscilloscope we set trigger pin as alert pin(CML_ERROR_EN1). Wait CML_FAULT error and get the waveform Blue single : CLK Red single : SDA Yellow single : BMC Power Green single : CML error

3. (1) CML_FAULT error at power-off

4. (2-1) CML_FAULT error at power-on moment

5. (2-2) CML_FAULT error at power-on moment

6. 3)SDA locked and BMC recover SDA
3)SDA locked and BMC recover SDA. And then BMC send first command to HSC. After first command, we see CML_FAULT error

7. Some questions need help to clearly: (a) Sometime CML_FAULT error at power-off moment and sometimes CML_FAULT error at power-on moment, Could you give us criterion of judged CML_FAULT?? (b) After power-on, why does the SDA lock to low?? Does CML_FAULT error cause by abnormal I2C single that BMC recover SDA? Please help to find the root-cause and suggest the solution.