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Magazyn Enter 1999 January
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ctchip34
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UMC482A.CFG
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1993-01-22
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2KB
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60 lines
; UM82C482A.CFG
INDEXPORT=22H
DATENPORT=24H
INDEX=81H ;Control Register A
;*******************************************************
BIT=76 ;CPU clock selection
00=CKOUT=CKIN
01=CKOUT=CKIN/2
10=CKOUT=CKIN/3
11=CKOUT=CKIN/4
BIT=5 ;Keyboard clock selection
0=KBCLK=OSC14/2
1=KBCLK is defined by Bit 7, Bit 6 of control register B
BIT=4 ;DMA address/data hold time.
0=1-2 T-state
1=2-3 T-state
BIT=3 ;Read only. This bit reflects the status of TURBO pin
1=high speed
0=low speed
BIT=210 ;AT bus clock selection
000=ATCLK=CLK2/12 (386) bzw. CLK2/6 (486)
001=ATCLK=CLK2/10 (386) bzw. CLK2/5 (486)
010=ATCLK=CLK2/8 (386) bzw. CLK2/4 (486)
011=ATCLK=CLK2/6 (386) bzw. CLK2/3 (486)
1X0=ATCLK=CLK2/4 (386) bzw. CLK2/2 (486)
10X=ATCLK=CLK2/4 (386) bzw. CLK2/2 (486)
111=ATCLK=CLK2/16 (386) bzw. CLK2/8 (486)
INDEX=82H ;Control Register B
;*******************************************************
BIT=76 ;Keyboard clock selection
; only if bit 5 of control register A is high!
00=KBCLK=CLK2/12 (386) bzw. CLK2/6 (486)
01=KBCLK=CLK2/8 (386) bzw. CLK2/4 (486)
10=KBCLK=CLK2/6 (386) bzw. CLK2/3 (486)
11=KBCLK=CLK2/4 (386) bzw. CLK2/2 (486)
BIT=5 ;Software flush 80486 internal cache
1=PFLUSH# is active to flush 80486 internal cache
BIT=43 ;TURBO function selection
00=CKOUT=CKIN, ICLK=CLK2/4 (80386), ICLK=CLK2/2 (80486)
01=CKOUT=CKIN/2 ICLK=CLK2/4 (80386), ICLK=CLK2/2 (80486)
1X=Nothing changed. TURBO function is controlled by 8742.
BIT=2 ;LOWA20# selection
0=LOWA20# from 8742
1=LOWA20# chipset logic emulates 8742 LOWA20# generation
BIT=10 ;I/O Command recovery time
00= 2BCLK
01= 4BCLK
10= 8BCLK
11=12BCLK