CY28341 Cypress Semiconductor, CY28341 Datasheet - Page 6

• Manufacturer Part Number: CY28341
• Description: Universal Single-Chip Clock Solution
• Manufacturer: Cypress Semiconductor

Document #: 38-07367 Rev. *A
Byte 2: PCI Clock Register
Byte 3: AGP/Peripheral Clocks Register
Table 5. Dial-a-Skew™ AGP(0:2)
Byte 4: Peripheral Clocks Register
Table 6. Dial-A-Ratio™ AGP(0:2)
Bit @Pup Pin#
Bit @Pup
7
6
5
4
3
2
1
0
Bit
7
6
5
4
3
2
1
0
7
6
5
4
3
2
1
0
1
1
0
0
1
1
1
1
0
1
1
0
0
1
1
1
@Pup
0
1
1
1
1
1
1
1
6,7,8 DARAG1 Programming these bits allow modifying the frequency ratio of the AGP(2:0), PCI(6:1, F) clocks
6,7,8 DARAG0
20
21
56
56
6,7,8
6,7,8
1
1
Pin#
21
20
21
8
7
6
DASAG (1:0)
DARAG (1:0)
Pin#
24_48M 1 = normal strength, 0 = high strength
10
18
17
15
14
12
11
Name
REF0
REF1
REF0
REF1
48M
00
01
10
00
01
10
11
11
DASAG0
DASAG1
24_48M
24_48M
48MHz
Name
AGP2
AGP1
AGP0
PCI_DRV
1 = normal strength, 0 = high strength
1 = normal strength, 0 = high strength
1 = normal strength, 0 = high strength
relative to the CPU clocks. See Table 6.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state. (K7 Mode only.)
1 = normal strength, 0 = high strength
1 = normal strength, 0 = high strength (K7 Mode only.)
Name
PCI_F
PCI6
PCI5
PCI4
PCI3
PCI2
PCI1
“0” = pin21 output is 24MHz. Writing a “1” into this register asynchronously changes the
frequency at pin21 to 48 MHz.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
default value. See Table 5.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
Programming these bits allow shifting skew of the AGP(0:2) signals relative to their
PCI clock output drive strength 0 = Normal, 1 = increase the drive strength 20%.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
1 = output enabled (running). 0 = output disabled asynchronously in a LOW state.
Description
Frequency Selection Default
Description
AGP(0:2) Skew Shift
Description
CU/AGP Ratio
–280 ps
+280 ps
+480 ps
Default
2.5/1
2/1
3/1
CY28341
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