AM79C90 Advanced Micro Devices, AM79C90 Datasheet - Page 49

• Manufacturer Part Number: AM79C90
• Description: CMOS Local Area Network Controller for Ethernet (C-LANCE)
• Manufacturer: Advanced Micro Devices

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Program example in BASIC to generate the hash filter, for multicast addressing, in the C-LANCE.
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0024 35 1D 86
0027 81 F2 04C1
002B 0B C3
002D D1 CD
002F FE C9
0031 75 E1
0033 FE CD
0035 75 D6
0037 B9 000A
003A D0 E0
003C D0 DC
003E E2 FA
0040 8A DC
0042 B1 03
0044 D2 EB
0046 B0 01
0048 80 E45 07
004B 8A CC
004D D2 E0
004F 08 01
0051 5D
0052 5A
0053 59
0054 5B
0055 58
0056 C3
0057
0057
REM
REM PROGRAM TO GENERATE A HASH NUMBER GIVEN AN ETHERNET ADDRESS
REM
DEFINT A–Z
DIM A(47): REM ETHERNET ADDRESS. 48 BITS.
DIM A$(6): REM INPUT FROM KEYBOARD
DIM C(32): REM CRC REGISTER–32 BITS
;
;
SETH30:
;
;
SETH40:
;
;
;
SETHASH ENDP
;
CSEG1
;
XOR
XOR
OR
ROR
DEC
JNZ
DEC
JNZ
FORMATION OF CRC COMPLETE, AL CONTAINS THE REVERSED HASH
CODE
MOV
SAL
RCR
LOOP
AH NOW CONTAINS THE HASH CODE
MOV
MOV
SHR
MOV
AND
MOV
SHL
OR
POP
POP
POP
POP
POP
RET
ENDS
END
AX,POLYL
DX,POLYH
AX,BX
BP,1
CL
SETH20
CH
SETH10
CX,10
AL,1
AH,1
SETH40
BL,AH
CL,3
BL,CL
AL,01H
AH,7H
CL,AH
AL,CL
[Dl + BX],AL
BP
DX
CX
BX
AX
Am79C90
;PUT CONTROL BIT IN CRC0
;ROTATE ADDRESS WORD
;DECREMENT BIT COUNTER
;DECREMENT WORD COUNTER
;REVERSE THE ORDER OF BITS IN AL
;AND PUT IT IN AH
;BL = HASH CODE, BH IS ALREADY ZERO
;DIVIDE HASH CODE BY 8
;TO GET TO THE CORRECT BYTE
;PRESET FILTER BIT
;EXTRACT BIT COUNT
;SHIFT BIT TO CORRECT POSITION
;SET IN HASH FILTER
AMD
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