am79c940 Advanced Micro Devices, am79c940 Datasheet - Page 85

• Manufacturer Part Number: am79c940
• Description: Media Access Controller For Ethernet Mace
• Manufacturer: Advanced Micro Devices

Notes:
1. Compatible filter modules, with a brief description of package type and features are included in the following section.
2. The resistor values are recommended for general purpose use and should allow compliance to the 10BASE-T specification for template fit and
3. Compatible AUI transformer modules, with a brief description of package type and features are included in the following section.
4. Active High indicates the external convertor should be turned off. The Disable Transceiver (DXCVR) output is used to indicate the active
jitter performance. However, the overall performance of the transmitter is also affected by the transmit filter configuration. All resistors are
± 1%.
network port. A high level indicates the 10BASE-T port is selected and the AUI port is disabled. A low level indicates the AUI port is selected
and the Twisted Pair interface is disabled.
Active Low: indicates the external converter should be turned off. The LNKST output can be used to indicate the active network
port. A high level indicates the 10BASE-T port is in the Link Fail state, and the external convertor should be on. A low level indicates the
10BASE-T port is in the Link Pass state, and the external convertor should be off.
ANLG +5 V
Am79C940
AVDD
0.1 F
AVSS
DXCVR
10BASE-T and 10BASE2 Configuration of Am79C940
RXPOL
LNKST
RXD–
RXD+
TXD+
TXD–
Optional
TXP+
TXP–
DO+
DO–
DI+
DI–
CI+
CI–
0.1 F
40.2
61.9
422
61.9
422
ANLG GND
ANLG GND
40.2
40.2
LINK OK
0.1 F
Am79C940
Note 2
40.2
1.21K
0.1 F
100
Transformer
Active High
Note 3
Active Low
Pulse
RX POL OK
Note 1
Filter
Filter
XMT
RCV
Transformer
Optional
Module
Filter &
1:1
1:1
See Am7996 Data Sheet
implementation details
for component and
Am7996
Note 4
10BASE2 DC/DC
10BASE2 MAU
DGTL +5 V
Convertor
Disable
Connector
TD+
TD–
RD+
RD–
RJ45
1
6
2
3
16235C-17
COAX
(BNC)
TAP
AMD
85