SBV5120 Cable modem

Motorola SB5120 surfboard
The CPU of the board uses TNETC4401. The tool to debug the CPU is EJTAG (non-DMA).
Picture showing JTAG and Pin1

Flash One 4MB 28F320C3
Firmware 4MB $90000000-$903FFFFFF
RAM 16MB $94000000-$94FFFFFF

SBV120 uses 14 pin EJTAG. It has reset pin. So a "reset" command can reset the modem. (Some modems reset might not work, a cycle power might needed. If a command needed after reset, them command should apply just after power on)

You are encouraged to use UJmodem to access this modem.
Definition Commands (USB JTAG NT 0.13):
TSBV5120.xml Backup firmware
getram 90000000 100000
getram 90100000 100000
getram 90200000 100000
getram 90300000 100000
save 90000000 400000

Disable watchdog be ready to program
SBV5120 has a watchdog and need to disable to do programming.
Create file named 5120p.usp
Type command 5120p
After this your SBV5120 is ready to program and you can program it in normal speed without trigger watchdog.

Program whole firmware.
ldram 90000000
program 90000000 400000

You can use "reset" to restart the modem. You can not use "cmpram" command to check if the programming is ok when it says "DEBUG ON"

Rescue SBV5120. When box not fire up. Normal programming will not work. First need to program boot. No watchdog exist in this case
ldram boot (Select proper boot file)
erase boot
sprogram boot (Slow programming)
ldram image0(Any tabes you have backed up)
program image0(Any tabs you want at normal speed)

Lasted Updated:December 31 2016

Vists since Jan 4,2009