ICS9250BF-28T IDT, Integrated Device Technology Inc, ICS9250BF-28T Datasheet - Page 4

• Manufacturer Part Number: ICS9250BF-28T
• Description: IC FREQ GENERATOR/BUFFER 56-SSOP
• Manufacturer: IDT, Integrated Device Technology Inc
• Type: Frequency Generatorr

Specifications of ICS9250BF-28T

• Frequency - Max: 133MHz
• Voltage - Supply: 3.135 V ~ 3.465 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 56-SSOP
• Frequency-max: 133MHz
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Output: -
• Input: -
• Other names: 9250BF-28T

Truth Table
Byte 3: ICS Reserved Functionality and frequency select register (Default as noted in PWD)
Note 1: For system operation, the BSEL lines of the CPU will program FS0, FS2 for the appropriate CPU speed, always
Note 2: "ICS RESERVED BITS" must be writtern as "0".
Note3: Undefined bits can be written either as "1 or 0"
ICS9250-28
F
S
0
0
B
1
1
1
1
i B
i B
i B
i B
i B
i B
i B
B
2
t i
t i
7 t
6 t
5 t
4 t
3 t
2 t
1 t
0
F
with SDRAM = 100MHz. After BIOS verifies the SDRAM is PC133 speed, then bit 0 can be written from the
default 0 to 1 to change the SDRAM output frequency from 100MHz to 133MHz. This will only change if the
CPU is at the 133MHz FSB speed as shown in this table. The CPU, 3V66, PCI, and IOAPIC clocks will be glitch
free during this transition, and only SDRAM will change.
S
0
0
0
1
1
1
0
C I
C I
C I
C I
C I
U
U
d n
d n
B
S
S
S
S
S
t i
0
0
0
0
1
1
1
1
F
f e
f e
R
R
R
R
R
X
X
S
0
0
1
1
0
n i
n i
e
e
e
e
e
1
e s
e s
e s
e s
e s
d e
d e
v r
v r
v r
v r
v r
i b
i b
d e
d e
d e
d e
d e
6 6
1
1
1
( t
( t
F
T
T
0 0
3 3
3 3
i b
i b
i b
i b
i b
S
0
0
0
0
C
1
1
1
1
6 .
C
s i r
N
N
0
L
( t
( t
( t
( t
( t
P
o
o
M
M
M
M
a t
K
U
e t
e t
N
N
N
N
N
e t
H
H
H
2 /
H
o
o
o
o
o
) 3
) 3
z
z
z
z
e t
e t
e t
e t
e t
F
) 2
) 2
) 2
) 2
) 2
S
0
0
0
0
1
1
1
1
1
1
1
1
1
S
T
T
0 0
0 0
3 3
0 0
D
C
s i r
R
L
C
M
M
M
M
a t
A
K
P
3 1
3 1
3 1
3 1
6
1
6
1
M
e t
H
H
H
H
M
2 /
U
. 6
. 6
0 0
0 0
. 3
. 3
. 3
. 3
D
z
z
z
z
H
C
6 6
6 6
0 .
2 3
2 3
0 .
2 3
2 3
e
z
L
c s
K
i t
6 6
6 6
6 6
6 6
t p
T
T
S
3
C
6 .
6 .
6 .
6 .
s i r
o i
3 1
3 1
3 1
D
V
1
1
1
1
1
M
L
n
M
M
M
M
0 0
0 0
0 0
0 0
0 0
a t
6 6
R
K
. 3
. 3
. 3
H
A
e t
3 /
H
H
H
H
0 .
0 .
2 3
0 .
0 .
0 .
2 3
2 3
z
M
z
z
z
z
3 3
3 3
3 3
3 3
T
3
6
6
6
6
6
6
6
6
M
T
. 6
. 6
. 6
C
V
. 6
. 6
. 6
. 6
. 6
3 .
3 .
3 .
3 .
s i r
P
H
L
6 6
6 6
6 6
6 6
6 6
6 6
6 6
6 6
6 6
I C
M
M
M
M
a t
z
K
e t
H
H
H
H
6 /
z
z
z
z
P
C
3
3
3
3
3
3
3
3
M
C I
. 3
. 3
. 3
. 3
. 3
. 3
. 3
. 3
H
T
8 4
8 4
8 4
8 4
8 4
T
3 3
3 3
3 3
3 3
3 3
3 3
3 3
3 3
L
z
C
s i r
K
M
L
M
M
M
M
a t
K
H
H
H
H
H
e t
2 /
I
z
z
z
z
z
O
3
3
3
3
3
3
3
3
M
A
. 3
. 3
. 3
. 3
. 3
. 3
. 3
. 3
H
P
3 3
3 3
3 3
3 3
3 3
3 3
3 3
3 3
z
C I
4 1
4 1
4 1
4 1
T
3 .
3 .
3 .
3 .
T
R
s i r
8 1
8 1
8 1
8 1
C
E
N
P
L
a t
F
o
M
M
M
M
W
K
X
X
e t
0
0
0
0
0
0
e t
H
H
H
H
D
1
z
z
z
z
3 3
3 3
3 3
3 3
T
I
T
O
C
3 .
3 .
3 .
3 .
s i r
A
L
M
M
M
M
P
a t
K
C I
e t
6 /
H
H
H
H
z
z
z
z