cy2275a Cypress Semiconductor Corporation., cy2275a Datasheet - Page 3

• Manufacturer Part Number: cy2275a
• Description: Pentium Clock Synthesizer/driver Desktop With Intel 82440lx With Dimms
• Manufacturer: Cypress Semiconductor Corporation.

Power Management Logic - Active when MODE pin is held ‘LOW’
Serial Configuration Map
Select Functions
X
0
0
1
1
Functional Description
Three-State
Test Mode
Note:
• The Serial bits will be read by the clock driver in the following
• Reserved and unused bits should be programmed to “0”.
• I
CPU_STOP
3.
order:
A6
2
1
C Address for the CY2275 is:
TCLK supplied on the XTALIN pin in Test Mode.
Byte 0 - Bits 7, 6, 5, 4, 3, 2, 1, 0
Byte 1 - Bits 7, 6, 5, 4, 3, 2, 1, 0
.
.
Byte N - Bits 7, 6, 5, 4, 3, 2, 1, 0
A5
1
X
0
1
0
1
PCI_STOP
A4
0
A3
1
Hi-Z
TCLK/2
CPU
0
1
1
1
1
PWR_DWN
A2
0
[3]
Hi-Z
TCLK/4
PCI, PCI_F
A1
0
Low
Low
Low
66/60 MHz
66/60 MHz
CPUCLK
A0
1
Outputs
Hi-Z
TCLK/2
SDRAM
R/W
----
Low
Low
33/30 MHz
Low
33/30 MHz
PCICLK
3
Hi-Z
TCLK
Byte 0: Functional and Frequency Select Clock
Register (1 = Enable, 0 = Disable)
Ref
Bit 7 --
Bit 6 --
Bit 5 --
Bit 4 --
Bit 3 --
Bit 2 --
Bit 1
Bit 0
Bit
Pin #
--
Stopped
Running
Running
Running
Running
Hi-Z
TCLK
PCICLK_F
IOAPIC
(Reserved) drive to ‘0’
(Reserved) drive to ‘0’
(Reserved) drive to ‘0’
(Reserved) drive to ‘0’
(Reserved) drive to ‘0’
(Reserved) drive to ‘0’
Bit 1
1
1
0
0
Stopped
Running
Running
Running
Running
Bit 0
1 - Three-State
0 - N/A
1 - Testmode
0 - Normal Operation
Other Clocks
Description
Off
Running
Running
Running
Running
Osc.
CY2275A
Off
Running
Running
Running
Running
PLLs