
CYW150
........................ Document #: 38-07177 Rev. *B Page 8 of 14
Note:
2. CPU and PCI frequency selections are listed in
Table 2 and
Table 6.
Table 6. Frequency Selections through Serial Data Interface Data Bytes
Input Conditions
Output Frequency
Spread On
Data Byte 0, Bit 3 = 1
CPU, SDRAM
Clocks (MHz)
PCI Clocks
(MHz)
Spread Percentage
Bit 2
SEL_3
Bit 6
SEL_2
Bit 5
SEL_1
Bit 4
SEL_0
1
133.3
33.3 (CPU/4)
± 0.5% Center
1
0
124
31 (CPU/4)
± 0.5% Center
1
0
1
150
37.5 (CPU/4)
± 0.5% Center
1
0
140
35 (CPU/4)
± 0.5% Center
1
0
1
105
35 (CPU/3)
± 0.5% Center
1
0
1
0
110
36.7 (CPU/3)
± 0.9% Center
1
0
1
115
38.3 (CPU/3)
± 0.5% Center
1
0
120
40 (CPU/3)
± 0.5% Center
0
1
100
33.3 (CPU/3)
± 0.5% Center
0
1
0
133.3
44.43 (CPU/3)
± 0.5% Center
0
1
0
1
112
37.3 (CPU/3)
± 0.5% Center
0
1
0
103
34.3 (CPU/3)
± 0.5% Center
0
1
66.8
33.4 (CPU/2)
± 0.5% Center
0
1
0
83.3
41.7 (CPU/2)
± 0.9% Center
0
1
75
37.5 (CPU/2)
± 0.5% Center
0
124
41.3 (CPU/3)
± 0.5% Center
Table 7. Select Function for Data Byte 0, Bits 0:1
Function
Input Conditions
Output Conditions
Data Byte 0
CPU_F, 1:2
PCI_F, PCI0:5
REF0:1,
IOAPIC0,_F
48 MHZ
24 MHZ
Bit 1
Bit 0
Normal Operation
0
14.318 MHz
48 MHz
24 MHz
Test Mode
0
1
X1/2
CPU/(2 or 3)
X1
X1/2
X1/4
Spread Spectrum
1
0
14.318 MHz
48 MHz
24 MHz
Tristate
1
Hi-Z