Fatal exception (28):问题

[TOPARM]

Fatal exception (28):
epc1=0x40101517, epc2=0x00000000, epc3=0x00000000, excvaddr=0x00000000, depc=0x00000000
rm match
del if0
bcn 0
del if1
usl
sul 0 0

ets Jan 8 2013,rst cause:4, boot mode:(3,5)

wdt reset
load 0x40100000, len 32024, room 16
tail 8
chksum 0x24
load 0x3ffe8000, len 2508, room 0
tail 12
chksum 0x53
ho 0 tail 12 room 4
load 0x3ffe89d0, len 1672, room 12
tail 12
chksum 0x8c
csum 0x8c
{lmode : sta(18:fe:34:9d:70:f3) + softAP(1a:fe:34:9d:70:f3)
add if0
dhcp server start:(ip:192.168.4.1,mask:255.255.255.0,gw:192.168.4.1)
add if1
bcn 100
scandone
add 0
aid 1
cnt

connected with GAOKE_3831cc, channel 3
dhcp client start...

您好，请问Fatal exception (28):可能是什么原因引起的，代码中没有while和长时间的延时，为什么会出现看门狗复位？