82815 GMCH
R
68
Datasheet
Bit
Description
15
SCS[5]# Buffer Strength (Row 5).
0 = Reserved
1 = 1.0x 0 or 2 load or 4 loads
Each Row is actually selected by a pair of chip select signals (SCSA[n]# and SCSB[n]#). The number of
SCS# loads for a given row can be determined from SPD data using the following equation:
Loads = 32 / (width of SDRAM devices in row)
14
SCS[4]# Buffer Strength (Row 4).
0 = Reserved
1 = 1.0x 0 or 2 load or 4 loads
13
SCS[3]# Buffer Strength (Row 3).
0 = Reserved
1 = 1.0x 0 or 2 load or 4 loads
12
SCS[2]# Buffer Strength (Row 2).
0 = Reserved
1 = 1.0x 0 or 2 load or 4 loads
11
SCS[1]# Buffer Strength (Row 1).
0 = Reserved
1 = 1.0x 0 or 2 load or 4 loads
10
SCS[0]# Buffer Strength (Row 0).
0 = Reserved
1 = 1.0x 0 or 2 load or 4 loads
9:8
SMAC[7:4]# Buffer Strength (Rows 4/5).
00 = 2.7x > 8 loads
01 = 1.7x 8 loads
10 = 1.0x 0 or 4 loads
11 = 1.0x 0 or 4 loads
Separate copies of these SMA*[7:4] “Command-Per-Clock” signals are provided for each DIMM. So the
loads for each copy are determined by the number of SDRAM devices on the corresponding DIMM (4, 8,
12, or 16 loads). The number of loads for each SMA*[7:4] signal group can be determined from SPD
data using the following equation:
Loads = (64 / (SDRAM Device Width for 1
st
row)) + (64 / (SDRAM Device Width for 2
nd
row))
7:6
SMAB[7:4]# Buffer Strength (Rows 2/3).
00 = 2.7x > 8 loads
01 = 1.7x 8 loads
10 = 1.0x 0 or 4 loads
11 = 1.0x 0 or 4 loads