Texas Instruments TMS320C6201 Reference Manual page 449

Figure 15–8. Connecting a Secondary JTAG Scan Path to an SPL
TDI
TMS
TCK
TRST
TDO
The TRST signal from the main scan path drives all devices, even those on
the secondary scan paths of the SPL. The TCK signal on each target device
on the secondary scan path of an SPL is driven by the SPL's DTCK signal. The
TMS signal on each device on the secondary scan path is driven by the respec-
tive DTMS signals on the SPL.
DTDO on the SPL is connected to the TDI signal of the first device on the sec-
ondary scan path. DTDI on the SPL is connected to the TDO signal of the last
device in the secondary scan path. Within each secondary scan path, the TDI
signal of a device is connected to the TDO signal of the device before it. If the
SPL is on a backplane, its secondary JTAG scan paths are on add-on boards;
if signal degradation is a problem, you may need to buffer both the TRST and
DTCK signals. Although less likely, you may also need to buffer the DTMS n
signals for the same reasons.
SPL
DTCK
DTDO0
DTMS0
DTDI0
DTDO1
DTMS1
DTDI1
DTDO2
DTMS2
DTDI2
DTDO3
DTMS3
DTDI3
Designing for JTAG Emulation
Emulation Design Considerations
JTAG 0
TDI
TMS
TCK
TRST
TDO
JTAG N
TDI
TMS
TCK
TRST
TDO
15-15