Philips Semiconductors
HECETA4 Temperature and voltage monitor
Product data sheet
NE1619
NAND-tree test
A NAND tree is provided in the NE1619 for Automated Test
Equipment (ATE) board level connectivity testing. The device is
placed into NAND tree test mode by powering up with Pin 9
(D–/NTEST_IN) held high. In this test mode Pin 16
(A0/RESET/NTEST_OUT) becomes the NAND-tree output and all
input pins become NAND-tree inputs as illustrated in Figure 12.
To perform a NAND tree test all pins should be initially driven low.
Then one-by-one toggle them high (and keep them high), starting
with the input closest to the output, cycling toward the farthest, the
NAND tree output will toggle with each input change.
SDA
SCL
VID0
VID1
VID2
VID3
VID4
Table 9. NAND-tree test vectors
VECTOR #
SDA
SCL
1
L
L
2
L
L
3
L
L
4
L
L
5
L
L
6
L
L
7
L
H
8
H
H
Figure 12. NAND-tree circuitry
VID0
L
L
L
L
L
H
H
H
VID1
L
L
L
L
H
H
H
H
VID2
L
L
L
H
H
H
H
H
VID3
L
L
H
H
H
H
H
H
VID4
L
H
H
H
H
H
H
H
NTEST_OUT
SL01232
NTEST_OUT
H
L
H
L
H
L
H
L
2004 Oct 05
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