Texas Instruments TMS320C6201 Reference Manual page 445

15.7.3 Configuring Multiple Processors
Figure 15–5. Multiprocessor Connections
JTAG Device
TDO TDI
Figure 15–5 shows a typical daisy-chained multiprocessor configuration,
which meets the minimum requirements of the IEEE 1149.1 specification. The
emulation signals in this example are buffered to isolate the processors from
the emulator and provide adequate signal drive for the target system. One of
the benefits of this type of interface is that you can generally slow down the test
clock to eliminate timing problems. You should follow these guidelines for
multiprocessor support:
The processor TMS, TDI, TDO, and TCK signals should be buffered
through the same physical package for better control of timing skew.
The input buffers for TMS, TDI, and TCK should have pullup resistors con-
nected to V to hold these signals at a known value when the emulator
CC
is not connected. A resistor value of 4.7 kΩ or greater is suggested.
Buffering EMU0 and EMU1 is optional but highly recommended to provide
isolation. These are not critical signals and do not have to be buffered
through the same physical package as TMS, TCK, TDI, and TDO. Unbuf-
fered and buffered signals are shown in this section (page 15-8 and page
15-9).
JTAG Device
TDO TDI
Connections Between the Emulator and the Target System
V CC
13
14
2
1
3
7
11
9
Designing for JTAG Emulation
V CC
Emulator Header
5
EMU0 PD
EMU1
4
TRST GND
6
TMS GND
8
TDI GND
10
TDO GND
12
TCK GND
TCK_RET
GND
15-11