[rescue] JTAG cable pinout for SUN CrayServer 6400

[Skeezics Boondoggle]

On Tue, 23 Aug 2005, "cyber-cray" wrote:

> Does someone have the pinout and cable spec of the JTAG cable that is
> used to control a CS6400 ? What connectors are used ?
> 
> I want to build such a cable, because they seem to be unavailable.

For posterity, here's the SSP-to-CS6400 JTAG+ cable pinout:

	JSCC				 Control Board
Pin	Function			Pin	Function
-------------------------------------------------------------
 1	SV_TCK		twisted		 1	BAC_TCK
 14	SV_TCK_L	 pair		 14	BAC_TCK_L
-------------------------------------------------------------
 2	no connection			 2	no connection
 15	no connection			 15	no connection
-------------------------------------------------------------
 3	SV_TMS		twisted		 3	BAC_TMS
 16	SV_TMS_L	 pair		 16	BAC_TMS_L
-------------------------------------------------------------
 4	SV_RST		twisted		 4	BAC_RST
 17	SV_RST_L	 pair		 17	BAC_RST_L
-------------------------------------------------------------
 5	SV_TAS		twisted		 5	BAC_TAS
 18	SV_TAS_L	 pair		 18	BAC_TAS_L
-------------------------------------------------------------
 6	SV_TDO		twisted		 6	BAC_TDI
 19	SV_TDO_L	 pair		 19	BAC_TDI_L
-------------------------------------------------------------
 7	no connection			 7	no connection
 20	no connection			 20	no connection
-------------------------------------------------------------
 8	SV_RCK_DIF	twisted		 8	BAC_RCK_DIF
 21	SV_RCK_DIF_L	 pair		 21	BAC_RCK_DIF_L
-------------------------------------------------------------
 9	SV_TDI_DIF	twisted		 9	BAC_TDO_DIF
 22	SV_TDI_DIF_L	 pair		 22	BAC_TDO_DIF_L
-------------------------------------------------------------
 10	MPRO				 10	MPRO
 23	GND				 23	GND
 11	no connection			 11	no connection
 24	no connection			 24	no connection
 12	GND				 12	GND
 25	DIFF_TRANS			 25	DIFF_TRANS
 13	no connection			 13	no connection
-------------------------------------------------------------

Both connectors are DB-25 male.  Maximum length should not exceed 3m 
(approx 18-20').

I made my own cable using three equal-length segments of Cat5 secured
every foot or so with electrical tape, and a pair of solder-type DB-25
shells, largely because I'm a complete idiot; why I didn't use the _much_
simpler crimp-type pins is beyond me... but anyway, after much fussing
about, my homemade cable worked great.  Because you only get 24 individual
strands with three 4-pair Cat5 cables, I left pin 13 disconnected.

Cheers,

-- Chris