Crystal LAN CS8920, Technical Reference Manual

Page: 43 / 67

AN84REV1 43
CS8920 Technical Reference Manual
3.3.1 IEEE Physical Address
The format of the 48-bit IEEE physical
address as expected by the MAC driver is
illustrated by the following example. (Must
be initialized by OEM before shipping
adapter.)
Example physical address:
000102030405h
Addr Word Description
1Ch 0100h bits[39-32], bits[47-40] of IEEE addr.
1Dh 0302h bits[23-16], bits[31-24] of IEEE addr.
1Eh 0504h bits[7-0], bits[15-8] of IEEE addr.
3.3.2 ISA Configuration Flags
The ISA Configuration Flags specify how
the CS8920 will utilize ISA system
resources.
Bit 15: Memory Mode Flag
Indicates the CS8920 will use shared
memory for IO operations. Refer to the
CS8920 Data Sheet for description of
shared memory interface. Default is
disabled.
Bit 14: Boot PROM Flag
Indicates a Boot PROM is installed. Refer
the CS8920 Data Sheet for a discussion of
the Boot PROM . (Must be initialized by
OEM before shipping adapter.)
Bit 13: Reserved (set to 0)
Bit 12: DMA Burst
Refer to the CS8920 Data Sheet for a
discussion of DMA Burst control. Default
is enabled.
Bits 11-10: Reserved (set to 0)
Bit 9: DMA Buffer Size
Indicates whether the DMA buffer size
should be 16K or 64K. Refer to the
CS8920 Data Sheet for a discussion of
DMA Buffer size. Default is 16K.
Bit 8: IOCHRDY Enable
Refer to the CS8920 Data Sheet for a
discussion of IOCHRDY control. Default
is enabled.
Bit 7: UseSA
Refer to the CS8920 Data Sheet for a
discussion of UseSA control. Default is
enabled.
Bits 6-4: DMA Channel Select
Refer to the CS8920 Data Sheet for a
discussion of DMA channel selection for
the CS8920. Default is DRQ4 (disabled).
Bits 3-0: IRQ Channel Select
Refer to the CS8920 Data Sheet for a
discussion of IRQ channel selection for the
CS8920. Default is IRQ 10.
3.3.3 PacketPage Memory Base
Bits 15-4: 12 MSB of Memory Base
Address
The twelve most significant bits of the 24-
bit address locating the base of the
CS8920’s PacketPage memory. The lower
twelve bits are assumed to be 0. Default is
0.