Principle analysis of single chip in voltage domain
（
Figure 5 Figure 6 below
）：
5
、
BM1387 Circuit diagram
6
、
BM1387 Chip Pin
Signal Description
Name
I/O
Active
Level
Description
1
NRSTO
O
L
Output to the chip of next level, for the loop
2
BO
O
H
Respond Busy Output
3
RI_A
I
N/A
Auxiliary Respond Input add diode and pulldown
4
Re
I
N/A
Respond Input. Schmitt input and internal pullup
4
