Motorola MPC5200 - Manual (Page 25)

MPC5200 FEC Device Driver KADAK M5200E-3
MPC5200 FEC Ethernet
Device Driver Data Sheet (continued)
Parameters ( continued )
Ethernet Address The 48-bit Ethernet address assigned to the network must be
defined. The most significant byte (see MSB in diagram) of the high 16
bits of the Ethernet address will be transmitted first; the least significant
byte (see
LSB in diagram) of the low 32 bits of the address will be
transmitted last.
IRQ-BC, IRQ-FEC Parameter IRQ-BC is the KwikNet IRQ identifier which defines how
the BestComm Ethernet receive task interrupt requests are vectored.
Parameter
IRQ-FEC is the KwikNet IRQ identifier which defines how the
FEC interrupt request is vectored. These parameters are used by the board
driver module
KN_BOARD.C to map logical device interrupts to the
underlying target hardware and operating system.
Note that device interrupts to the PowerPC are funneled through one or
more PowerPC exception vectors. Multiple devices can generate
interrupts through a single PowerPC exception vector.
AMX PPC 32 handles the separation of interrupts and their vectoring
through a single linear array referred to as the AMX Vector Table.
Consequently, when using
KwikNet with AMX PPC 32 , the AMX vector
numbers are used as the KwikNet IRQ identifiers.
If you are using the KwikNet Porting Kit, the assignment of IRQ identifiers
must be done by you as part of your overall system design.
Buffers These parameters define the number of transmit and receive buffers which
the BestComm DMA Engine must be configured to support. Descriptors
for these transmit and receive buffers will be allocated in the BestComm
Buffer Descriptor Tables. Unless you edit the definitions in header file
M5200E.H , you must specify a minimum of one transmit buffer and two
receive buffers. Two transmit buffers and eight receive buffers are
frequently sufficient.
BestComm FEC descriptors can only be allocated once. Hence, the
descriptors are allocated the first time that the network interface is opened.
For prebuilt networks, the descriptors will be allocated the first time that
KwikNet is started. For networks added at runtime, the descriptors will be
allocated upon your first call to KwikNet procedure kn_ifopen() after
having added a network interface with a call to kn_ifadd() .