ADSP-21061 Analog Devices, ADSP-21061 Datasheet - Page 13

• Manufacturer Part Number: ADSP-21061
• Description: ADSP-2106x SHARC DSP Microcomputer Family
• Manufacturer: Analog Devices

Connecting CLKIN to Pin 4 of the EZ-ICE header is optional.
The emulator only uses CLKIN when directed to perform op-
erations such as starting, stopping and single-stepping multiple
ADSP-2106x in a synchronous manner. If you do not need these
operations to occur synchronously on the multiple processors,
simply tie Pin 4 of the EZ-ICE header to ground.
If synchronous multiprocessor operations are needed and
CLKIN is connected, clock skew between the multiple ADSP-
21061x processors and the CLKIN pin on the EZ-ICE header
must be minimal. If the skew is too large, synchronous operations
may be off by one or more cycles between processors. For syn-
chronous multiprocessor operation TCK, TMS, CLKIN and
EMU should be treated as critical signals in terms of skew, and
CLKIN
TRST
EMU
TMS
TCK
TDO
TDI
*
*
*
OPEN DRAIN DRIVER OR EQUIVALENT, i.e.,
5k
5k
TDI
TDI
TDO
TDO
TDI
TDI
should be laid out as short as possible on your board. If TCK,
TMS and CLKIN are driving a large number of ADSP-2106x
(more than eight) in your system, then treat them as a clock tree
using multiple drivers to minimize skew. (See Figure 7, JTAG
Clock Tree, and Clock Distribution in the High Frequency
Design Considerations section of the ADSP-2106x User’s
Manual, Second Edition.)
If synchronous multiprocessor operations are not needed (i.e.,
CLKIN is not connected), just use appropriate parallel termina-
tion on TCK and TMS. TDI, TDO, EMU and TRST are not
critical signals in terms of skew.
For complete information on the SHARC EZ-ICE, see the ADSP-
21000 Family JTAG EZ-ICE User’s Guide and Reference.
TDO
TDO
TDI
TDI
EMU
TDO
TDO
ADSP-21061/ADSP-21061L
SYSTEM
CLKIN