Service Modes, Error Codes, and Fault Finding
5.
POWERDOWN SEQUENCE
The following figure shows the power-down sequence
flowchart:
Figure 5-13 Power-down flowchart
The power-down condition is detected by the MT5392
POWER_DOWN signal which is an interrupt pin. A “low” level
on this line signifies that power-down is detected. The two
major activities that occur over this operation is the muting of
audio output and write protecting the system flash and
EEPROM.
DC PROTECTION
The following figure shows the DC_PROT interrupt flowchart:
Figure 5-14 DC Protection flowchart
5.6.10 SSB replacement
Follow the instructions in the flowchart in case a SSB has to be
swapped.
S
TART
MT5
3
92 Detect
s
POWER_DOWN INT
POWER_DOWN INT
bas
ed on f
a
lling
edge trigger
W
a
it for
impending
Power Off
Note: To
Avoid F
a
l
s
e
Triggering
Write Protect Fl
as
h
a
nd
S
y
s
tem EEPROM
M
u
te A
u
dio O
u
tp
u
t
S
y
s
tem Idle
Reconfirm
POWER_DOWN
= LOW?
Ye
s
No
END
1
8
490_200_09040
8
.ep
s
09040
8
S
TART
Note: To
Avoid F
a
l
s
e
Triggering
Log Error Code
M
u
te A
u
dio O
u
tp
u
t
Go to
S
TANDBY
Check
DC_PROT = LOW
for
3
s
ec?
Ye
s
No
END
DC Protection
[Protection]
H_17740_0
3
7.ep
s
24010
8
