
Am79C972
87
Figure 49.
Pattern Match RAM
There are two general methods to place the PCnet-
FAST
+ into the Magic Packet mode. The first is the soft-
ware method. In this method, either the BIOS or other
software, sets the MPMODE bit (CSR5, bit 1). Then
PCnet-
FAST
+ controller must be put into suspend
mode (see description of CSR5, bit 0), allowing any
current network activity to finish. Finally, either PG must
be deasserted (hardware control) or MPEN (CSR5, bit
2) must be set to 1 (software control).
Note:
FASTSPNDE (CSR7, bit 15) has no meaning in
Magic Packet mode.
The second method is the hardware method. In this
method, the MPPEN bit (CSR116, bit 4) is set at power
up by the loading of the EEPROM. This bit can also be
set by software. The PCnet-
FAST
+ will be placed in the
Magic Packet Mode when either the PG input is
deasserted or the MPEN bit is set. WUMI output will be
asserted when the PCnet-
FAST
+ is in the Magic
Packet mode. Magic Packet mode can be disabled at
any time by asserting PG or clearing MPEN bit.
When the PCnet-
FAST
+ controller detects a Magic
Packet frame, it sets the MPMAT bit (CSR116, bit 5),
the MPINT bit (CSR5, bit 4), and the PME_STATUS bit
(PMCSR, bit 15). The setting of the MPMAT bit will also
cause the RWU pin to be asserted and if the PME_EN
or the PME_EN_OVR bits are set, then the PME will be
asserted as well. If IENA (CSR0, bit 6) and MPINTE
(CSR5, bit 3) are set to 1, INTA will be asserted. Any
one of the four LED pins can be programmed to indi-
cate that a Magic Packet frame has been received.
BCR 47
BCR 46
BCR 45
BCR Bit Number 15 8 7 0 15 8 7 0 15 8
PMR_B4
PMR_B3
PMR_B2
PMR_B1
PMR_B0
Pattern Match
RAM Address
Pattern Match RAM Bit Number
39 32 31 24 23 16 15 8 7 0
Comments
0
P3 pointer
P2 pointer
P1 pointer
P0 pointer
Pattern Enable
bits
First Address
1
P7 pointer
P6 pointer
P5 pointer
P4 pointer
X
Second
Address
2
Data Byte 3
Data Byte 2
Data Byte1
Data Byte 0
Pattern Control
Start Pattern
P
1
2+n
Data Byte 4n+3
Date Byte 4n+2
Data Byte 4n+1
Data Byte 4n+0
Pattern Control
End Pattern P
1
J
Data Byte 3
Data Byte 2
Data Byte 1
Data Byte 0
Pattern Control
Start Pattern P
k
J+m
Data Byte 4m+3 Data Byte 4m+2 Data Byte 4m+1 Data Byte 4m+0
Pattern Control
End Pattern P
k
63
Last Address
7 6 5 4 3 2 1 0
EOP SKIP MASK
21485C-52