am79c970 Advanced Micro Devices, am79c970 Datasheet - Page 78

• Manufacturer Part Number: am79c970
• Description: Pcnettm-pci Single-chip Ethernet Controller For Pci Local Bus
• Manufacturer: Advanced Micro Devices

Pin 120 (RST) is the first input to the NAND tree. Pin 117
(INTA) is the second input to the NAND tree, followed by
pin 121 (CLK). All other PCI bus signals follow, counter-
clockwise, with pin 57 (AD0) being the last. Pins labeled
RST must be asserted low to start a NAND tree test se-
quence. Initially, all NAND tree inputs except RST
should be driven high. This will result in a high output at
the NOUT pin. If the NAND tree inputs are driven from
high to low in the same order as they are connected to
build the NAND tree, NOUT will toggle every time an ad-
ditional input is driven low. NOUT will change to a
ZERO, when INTA is driven low and all other NAND tree
inputs stay high. NOUT will toggle back to high, when
CLK is additionally driven low. The square wave will
Input #
NAND
Tree
10
11
12
13
14
15
16
17
1
2
3
4
5
6
7
8
9
Pin #
120
117
121
123
126
128
129
131
132
10
12
13
2
3
5
6
7
C/BE3
IDSEL
Name
AD31
AD30
AD29
AD28
AD27
AD26
AD25
AD24
AD23
AD22
INTA
REQ
GNT
RST
CLK
Table 9. NAND Tree Configuration
Input #
NAND
Tree
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
P R E L I M I N A R Y
Am79C970
Pin #
15
16
18
19
21
22
23
24
25
26
27
28
29
31
32
34
35
NC and all power supply pins are not part of the NAND
tree. Table 9 shows the complete list of pins connected
to the NAND tree.
continue until all NAND tree inputs are driven low.
NOUT will be high, when all NAND tree inputs are
driven low.
Note that some of the pins connected to the NAND tree
are outputs in normal mode of operation. They must not
be driven from an external source until the PCnet-PCI
controller is configured for NAND tree testing.
DEVSEL
FRAME
C/BE2
C/BE1
TRDY
STOP
LOCK
PERR
SERR
AD18
AD17
AD16
Name
AD21
AD20
AD19
IRDY
PAR
Input #
NAND
Tree
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
Pin #
36
38
39
40
41
42
44
45
47
48
49
51
52
53
54
56
57
C/BE0
Name
AMD
AD15
AD14
AD13
AD12
AD11
AD10
AD9
AD8
AD7
AD6
AD5
AD4
AD3
AD2
AD1
AD0
1-945