Upgrading Your Modem 119
Kernel Recovery Mode
Your modem is equipped with ZyXEL’s exclusive Kernel
Recovery Mode. This unique feature enables quick recovery from
failed flash uploads. With other modems, a failed flash upload
usually results in the user having to return the modem to the factory
for repair.
In the unlikely event that your modem fails to respond to AT
commands after upgrading the flash EPROM:
1.
Turn off the modem.
2.
Press the D/V button while turning on the modem, then release
the button after 5 seconds.
A Kernel Program responsible for the update process takes
control of the modem. It accepts a limited set of AT commands,
including the ATUPX command.
3.
Repeat steps 1 through 9 from the previous directions above to
upload a file that contains the valid firmware for your modem.
Summary of Contents for U-336E
Page 1: ...U 336E User s Manual Version 1 0 Mar 1997 ZyXEL ACCESSING INTERNET INTRANET ...
Page 12: ...xii 12 Index 124 ...
Page 18: ...6 Introduction ...
Page 24: ...12 Installation ...
Page 42: ...30 Leased Line Operation ...
Page 56: ...44 Special Functions ...
Page 118: ...106 Status Registers Result Codes ...
Page 135: ...Connector Pinouts 123 ...