DCT 2500

Motorola (GI) produced DCT 2500 is next generation of CATV STB.
The CPU of the board uses Broadcom BCM7115. The tool to debug the CPU is EJTAG(DMA).

Picture showing JTAG is connected
Flash One 4MB or 8MB chips 28F640J3/28F320J3
Firmware 4MB/8MB $90000000-$907FFFFF
NVRAM 256KB $98000000-$9803FFFF
RAM 16MB $80000000-$81000000

DCT2500 uses 14 pin EJTAG. It has reset pin. So a "reset" command can reset the box.(Some boxes reset might not work, a cycle power might needed)
Sometime you need to remove the CATV cable to program reliably

Definition in usbjtag.def Commands (usbjtag 0.09 DCTTest.dll 0.41):
Name=DCT2500
DLL=DCTTest.dll
Memory=Ram,0,0x80000000,0x1000000
Memory=NVRAM,0,0x98000000,0x40000
Memory=boot,1,0x90000000,0x20000
Memory=plat,1,0x90020000,0x160000
Memory=app1,1,0x90180000,0x80000
Memory=app2,1,0x90200000,0x20000
Memory=app3,1,0x90220000,0x20000
Memory=app4,1,0x90240000,0x20000
Memory=rsvd,1,0x90260000,0x1a0000
Programram=0x80200000
Init=0xfffe072c,0
Init=0xfffe7000,0x1000000e
Init=0xfffe7004,0x02000011
Init=0xfffe7008,0x1c000000
Init=0xfffe700c,0x02000011
Init=0xfffe7018,0x18000005
Init=0xfffe701c,0x02000019
Init=0xfffe7020,0x18000005
Init=0xfffe7024,0x02000015
Endian=Big
IRLength=5

This is used only when boot is erased
Test:
Name=DMABoot
Memory=boot,1,0xbfc00000,0x200000
Endian=Big
IRLength=5
Protocol=EJTAG
DMA=Yes
ProbTrap=1
Init=0xff300000,0x1A
 Backup nvram
getram nvram
save nvram

Restore nvram
ldram nvram
setram nvram
reset

Backup firmware
getram 90000000 400000
save 90000000 400000

Program whole firmware
detect
ldram 90000000
program 90000000 400000
cmpram 90000000 400000(DMA allow cmpram in DEBUG ON mode)

Configure 2.54 firmware
detect (If you just finish another tab and screen shows DEBUG ON, no need to type detect)
ldram plat (Initial backup of 2.54 firmware)
firm254
program plat
cmpram plat
reset

Program platform firmware.
detect (If you just finish another tab and screen shows DEBUG ON, no need to type detect)
ldram plat
program plat
cmpram plat
reset

Rescue DCT2500. When box not fire up. Normal programming will not work. First need to program boot.
Go to Tools->Config and select "DMABoot" Start application
detect
ldram bfc00000 Load the boot
erase bfc00000 20000
sprogram bfc00000 20000(Slow programming)
reset Go to Tools->Config and select "DCT2500" Start application
detect
ldram plat(Any tabes you have backed up)
program plat(Any tabs you want in normal speed)

            

Lasted Updated:December 31 2016

Vists since Jan 4,2009