Motorola MVME2300 Series 用户手册
2-36
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Raven PCI Bridge ASIC
2
MPC Arbiter Control Register
This register is not used in MVME2300 series boards.
Prescaler Adjust Register
PADJ
Prescaler Adjust. Used to specify a scale factor for the
prescaler to ensure that the time base for the bus timer is
1 MHz. The scale factor is calculated as follows:
prescaler to ensure that the time base for the bus timer is
1 MHz. The scale factor is calculated as follows:
PADJ = 256 - Clk,
where Clk is the frequency of the CLK input in MHz. This
register should be written with the value $BE, indicating
a 66MHz MPC bus.
register should be written with the value $BE, indicating
a 66MHz MPC bus.
Address
$FEFF000C
Bit
0 1 2 3 4 5 6 7 8 9
1
0
0
1
1
1
1
2
2
1
3
3
1
4
4
1
5
5
1
6
6
1
7
7
1
8
8
1
9
9
2
0
0
2
1
1
2
2
2
2
3
3
2
4
4
2
5
5
2
6
6
2
7
7
2
8
8
2
9
9
3
0
0
3
1
1
Name
MARB
BREN2
BREN1
BREN0
PK
EN
EN
PK
MD
MD
GLM
D
BAMD
DEF
M
1
DEF
M
0
Operation
R
R
R
R
R
R
R
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R
R
R/W
R/W
Reset
$00
$00
0
0
0
0
0
1
1
1
0
0
0
1
0
0
1
1
Address
$FEFF0010
Bit
0 1 2 3 4 5 6 7 8 9
1
0
0
1
1
1
1
2
2
1
3
3
1
4
4
1
5
5
1
6
6
1
7
7
1
8
8
1
9
9
2
0
0
2
1
1
2
2
2
2
3
3
2
4
4
2
5
5
2
6
6
2
7
7
2
8
8
2
9
9
3
0
0
3
1
1
Name
PADJ
Operation
R
R
R
R/W
Reset
$00
$00
$00
$B4