Motorola MVME2300 Series 用户手册
Programming Model
http://www.motorola.com/computer/literature
3-35
3
DRAM Base Register
RAM A/B/C/D BASE
These control bits define the base address for their block’s
DRAM. RAM A/B/C/D BASE bits 0-7/8-15/16-23/24-
31 correspond to PowerPC 60x address bits 0 - 7. For
larger DRAM sizes, the lower significant bits of A/B/C/D
BASE are ignored. This means that the block’s base
address will always appear at an even multiple of its size.
Note that bit 0 is MSB.
DRAM. RAM A/B/C/D BASE bits 0-7/8-15/16-23/24-
31 correspond to PowerPC 60x address bits 0 - 7. For
larger DRAM sizes, the lower significant bits of A/B/C/D
BASE are ignored. This means that the block’s base
address will always appear at an even multiple of its size.
Note that bit 0 is MSB.
Also note that the combination of RAM_X_BASE and
ram_x_siz should never be programmed such that
DRAM responds at the same address as the CSR,
ROM/Flash, External Register Set, or any other slave on
the PowerPC bus.
ram_x_siz should never be programmed such that
DRAM responds at the same address as the CSR,
ROM/Flash, External Register Set, or any other slave on
the PowerPC bus.
CLK Frequency Register
CLK FREQUENCY
These bits should be programmed with the hexadecimal
value of the operating CLOCK frequency in MHz (i.e.
$42 for 66MHz). When these bits are programmed this
way, the chip’s prescale counter produces a 1MHz output.
value of the operating CLOCK frequency in MHz (i.e.
$42 for 66MHz). When these bits are programmed this
way, the chip’s prescale counter produces a 1MHz output.
Address
$FEF80018
Bit
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Name
RAM A BASE
RAM B BASE
RAM C BASE
RAM D BASE
Operation
READ/WRITE
READ/WRITE
READ/WRITE
READ/WRITE
Reset
0 PL
0 PL
0 PL
0 PL
Address
$FEF80020
Bit
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
Name
CLK
FREQUENCY
0
0
0
0
0
0
0
po
r
r
Operation
READ/WRITE
READ ZERO
READ ZERO
R
R
R
R
R
R
R
R/
C
C
Reset
42 P
X
X
X
X
X
X
X
X
X
1 P