Intel IXP2800 and IXP2850 Network Processors
Signal Description
40
Datasheet
3.2.10
Test and JTAG Signals
JTAG is the IEEE 1149.1 test access port. The JTAG input signals have a weak pullup resistor
internal to the chip, so that any input that is not terminated, is interpreted as a high. Other test
signals are network processor specific, for manufacturing use only. See
Table 15.PAS1_VCCA
1
DLL power. Should be generated by filtering VCC with an LC network
PAS2_VCCA
1
DLL power. Should be generated by filtering VCC with an LC network
PAS3_VCCA
1
DLL power. Should be generated by filtering VCC with an LC network
VREF_QDR0
2
QDR reference voltage.
VREF_QDR1
2
QDR reference voltage.
VREF_QDR2
2
QDR reference voltage.
VREF_QDR3
2
QDR reference voltage.
VCCR
14
RDRAM core processor.
VCCRA
6
RDRAM clean power. Should be generated by filtering VCC with an LC
VCCRIO
9
RDRAM I/O power.
PAR0_PADVREFA
1
RDRAM reference voltage.
PAR0_PADVREFB
1
RDRAM reference voltage.
PAR1_PADVREFA
1
RDRAM reference voltage.
PAR1_PADVREFB
1
RDRAM reference voltage.
PAR2_PADVREFA
1
RDRAM reference voltage.
PAR2_PADVREFB
1
RDRAM reference voltage.
Total Power Supply
Pins
655
Table 14. Power Supply Pins (Sheet 2 of 2)
Signal Names
Total
Pin Descriptions
Table 15. Test and JTAG Signals (Sheet 1 of 2)
Signal Name
I/O
Description
Number
JTAG_TCK
I
Test interface reference clock that times all the transfers on
the JTAG test interface.
1
JTAG_TMS
I
Test interface mode select. Tms causes state transitions in
the test access port (TAP) controller.
1
JTAG_TDI
I
Test interface data input. Tdi is the serial input through
which JTAG instructions and test data enter the JTAG
interface.
1
JTAG_TDO
OZ
Test interface data output. Tdo is the serial output through
which test instructions and data from the test logic leave
the network processor.
1