SLUSE48B May 2021 – November 2023 BQ79652-Q1 , BQ79654-Q1 , BQ79656-Q1
PRODUCTION DATA
A tone is a fixed number of couplets (pulses) with a specified polarity (all “+” or all “–”) sent through the differential vertical interface COMH and COML ports. Tone is used on stack devices as only the COMH/L ports are accessible. The number of couplets for transmission is always greater than the number of couplets needed for detection.
There are four communication tones corresponding to the four communication pings. They are WAKE tone, SLEEPtoACTIVE tone, SHUTDOWN tone, and HW_RESET tone. In addition to the communication tones, there are two extra tones related to device fault status: Heartbeat tone and Fault tone. These two fault status tones are only available in SLEEP mode. See Section 9.3.6.2.3.3 for details.