*Notice: The information in this document is subject to change without notice
Tsi301
Notes
Tsi301 HyperTransport to PCI User Manual
3-20
Note:
Pin order for signal setting—
TRST_N, TRISTATE_N, TMODE[3], TMODE[2], TMODE[1], TMODE[0]
Note:
Not all of the above conditions are exclusive. For example, the HyperTransport PCI bridge
can be in internal scan mode and in scan chain output mode simultaneously.
3.12.1 JTAG Test Mode
In
Pass2
, the HyperTransport PCI bridge implements JTAG in accordance with IEEE Standard 1149.1. A
BSDL description of the JTAG chain is available from API NetWorks.
3.12.2 Tristate
All HyperTransport PCI bridge outputs can be put in a tristate mode to put the chip into a quiescent state.
There are three groups of outputs:
•
scan chain
•
nandtree
•
other
Various combinations of these three groups can be tristated. See Table 3.8 for details.
3.12.3 Parametric Nandtree
On the HyperTransport PCI bridge, inputs and the input side of bidirectional I/Os go to parametric
nandtrees which allow parametric testing of V
il
and V
ih
as well as some AC timing measurements. Refer to
Table 3.8 for information about enabling the parametric nandtree test mode.
There are three different nandtrees:
•
HyperTransport I/Os—the output is DBGOUT2
•
PCI I/Os—the output is P_REQ_OUT_N
•
Any other signals—the output is DBGCLK
A version of the HyperTransport nandtree output that provides a pulse every time the HyperTransport
nandtree output changes is output on TDO. This allows some characterization of the speed of the chip.
Note:
In Pass2, there is only one nandtree and its output is DBGCLK. There is also a version of the
nandtree on DBGOUT[16] which pulses once for every nandtree output transition. DBGCLK is
reserved for use by API NetWorks.
The following inputs/bidirects are not covered by the nandtree test:
•
TMODE3
•
TMODE2
Signal Setting
Test Mode
01xxx0
Normal mode—Functional mode
11xxxx
JTAG mode—JTAG test mode
0000xx
Tristate mode—Tristate all outputs
0010xx
Parametric nandtree mode—Tristate all outputs except for nandtree outputs
0001xx
Scan chain output mode—Tristate all outputs except for scan chain outputs
0011xx
Powerdown inputs mode—Tristate all outputs, powerdown inputs
0xxx11
Internal scan mode—Tester bypass mode, enable scan shifting. This setting is used while
scanning in/out of the internal scan chains
0xxx01
Tester bypass mode—Disable scan. This setting is used for the internal scan capture cycles
Table 3.8 HyperTransport PCI Bridge Test Modes