SL28748
DOC#: SP-AP-0017 (Rev. AA)
Page 5 of 19
Control Registers
Byte 0: Control Register 0
Bit
@Pup
Name
Description
7
HW
FS
CPU Frequency Select Bit, set by HW
0 = 133MHz, 1= 100MHz
6
0
RESERVED
5
1
RESERVED
4
0
iAMT_EN
iAMT Enable
0 = Legacy Mode, 1 = iAMT Enabled
3
0
RESERVED
2
0
SRC_Main_SEL
Select source for SRC clock
0 = SRC_MAIN = PLL1, PLL3_CFG Table applies
1 = SRC_MAIN = PLL3, PLL3_CFG Table does not apply
1
0
SATA_SEL
Select source of SATA clock
0 = SATA = SRC_MAIN, 1= SATA = PLL4
0
1
PD_Restore
Save configuration when PD# is asserted
0 = Config. cleared, 1 = Config. saved
Byte 1: Control Register 1
Bit
@Pup
Name
Description
7
1
RESERVED
6
0
PLL1_SS_DC
Select for down or center SS
0 = Down spread, 1 = Center spread
5
0
PLL3_SS_DC
Select for down or center SS
0 = Down spread, 1 = Center spread
4
0
PLL3_CFB3
CFB Bit [4:1] only applies when SRC_Main_SEL = 0 (Byte 0, bit 2 =0)
See Table 4 on page 9 for Configuration.
3
0
PLL3_CFB2
2
1
PLL3_CFB1
1
0
PLL3_CFB0
0
1
RESERVED
Byte 2: Control Register 2
Bit
@Pup
Name
Description
7
1
REF_OE
Output enable for REF
0 = Output Disabled, 1 = Output Enabled
6
1
RESERVED
5
1
RESERVED
4
1
RESERVED
3
1
RESERVED
2
1
RESERVED
1
RESERVED
0
1
RESERVED
Byte 3: Control Register 3
Bit
@Pup
Name
Description
7
1
RESERVED
6
1
RESERVED
5
1
RESERVED