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AMD-761™ System Controller Programmer’s Interface
Chapter 2
AMD-761™ System Controller Software/BIOS Design Guide
24081D—February 2002
Preliminary Information
DRAM Mode/Status
Dev0:F0:0x58
Register Description
This register provides general mode control and status reporting of the DRAM system.
Note that some bits of this register are not initialized at reset time, and all bits must be initialized by BIOS for proper
operation. This action should be done prior to attempting DRAM access.
31
30
29
28
27
26
25
24
Bit
Clk_Dis5
Clk_Dis4
Clk_Dis3
Clk_Dis2
Clk_Dis1
Clk_Dis0
SDRAM_Init
Reserved
Reset
0
0
0
0
0
0
0
0
R/W
R/W
R/W1S
R
23
22
21
20
19
18
17
16
Bit
Mode_Reg
_ Status
STR_Control
Burst_Ref_En
Ref_Dis
Cyc_Per_Ref
Reset
0
0
0
X
X
X
X
X
R/W
R/W1S
R/W
15
14
13
12
11
10
9
8
Bit
Reserved
Reset
0
0
0
0
0
0
0
0
R/W
R
7
6
5
4
3
2
1
0
Bit
CS7_X4Mode CS6_X4Mode CS5_X4Mode CS4_X4Mode CS3_X4Mode CS2_X4Mode CS1_X4Mode CS0_X4Mode
Reset
X
X
X
X
X
X
X
X
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W