Force SYS68K/CPU-30 R4, Техническое справочное руководство

Страница: 101 / 209

Hardware Description SYS68K/CPU-30 R4 Technical Reference Manual
Page 88
3.13 The Local Area Network Interface
The CPU board offers a Local Area Network (LAN) interface. The LAN
interface consists of an Am7990 LANCE (Local Area Network
Controller for Ethernet), an Am7992 SIA (Serial Interface Adapter), two
32-Kbyte static RAMs, and control logic. The SRAMs provide a
64-Kbyte data buffer between the LANCE and the local 68030 CPU, thus
improving overall performance and reducing the risk of network overruns
or underruns. Logic on the CPU board arbitrates which device - CPU or
LANCE - gains mastership of the SRAM buffer.
3.13.1 Features of the
Ethernet
Interface
- Compatibility to IEEE 802.3/Ethernet
- Data rate of 10 Mbit per second
- DMA capability
- Interrupt generation
- 64 Kbytes of Local Buffer RAM
3.13.1.1 Ethernet
Address
A 48-bit Ethernet address has been assigned to your CPU-30 R4 board.
This Ethernet address has a general structure which ensures a unique
number assignment for every board and is calculated from the board
serial number.
The unique Ethernet address is displayed by the banner when entering the
FGA Boot debugger. FGA Boot also provides a utility function to get the
CPU board’s Ethernet address (see “#40 (0x28) Get Ethernet Number”
on page 196).
Figure 4: The 48-bit (6-byte) Ethernet address
47 40 39 32 31 24 23 16 15 8 7 0
0 0 8 0 4 2
Byte 5 4 3 2 1 0
3 0 X X X X
These 3 bytes always remain
00
16
:80
16
:42
16
Specific Machine:
03
16
for
SYS68K/CPU-30 R4
These 2 bytes are
consecutively
numbered.