CY28441
Clock Generator for Intel Alviso Chipset
Features
• Compliant to Intel CK410M
• Supports Intel Pentium
®
-M CPU
• Selectable CPU frequencies
• Differential CPU clock pairs
• 100 MHz differential SRC clocks
• 96 MHz differential dot clock
• 48 MHz USB clocks
• SRC clocks independently stoppable through
CLKREQ#[A:B]
CPU
x2 / x3
SRC
x6 / x7
PCI
x6
REF
x1
DOT96
x1
USB_48
x1
• 33 MHz PCI clock
• Low-voltage frequency select input
• I
2
C support with readback capabilities
• Ideal Lexmark Spread Spectrum profile for maximum
electromagnetic interference (EMI) reduction
• 3.3V power supply
• 56-pin TSSOP package
Block Diagram
XIN
XOUT
CPU_STP#
PCI_STP#
CLKREQ[A:B]#
FS_[C:A]
VTT_PWRGD#
IREF
Pin Configuration
VDD_PCI
VSS_PCI
PCI3
VDD_CPU
PCI4
CPUT[0:1], CPUC[0:1],
CPU(T/C)2_ITP]
PCI5
VDD_SRC
VSS_PCI
SRCT[0:5], SRCC[0:5]
VDD_PCI
PCIF0/ITP_EN
PCIF1
VTT_PWRGD#/PD
VDD_PCI
VDD_48
PCI[2:5]
USB_48/FS_A
VDD_PCIF
VSS_48
PCIF[0:1]
DOT96T
DOT96C
VDD_48 MHz
FS_B/TEST_MODE
DOT96T
SRCT0
DOT96C
SRCC0
USB_48
SRCT1
SRCC1
VDD_SRC
SRCT2
SRCC2
SRCT3
SRCC3
SRC4_SATAT
SRC4_SATAC
VDD_SRC
VDD_REF
REF
XTAL
OSC
PLL1
PLL Ref Freq
Divider
Network
PD
PLL2
SDATA
SCLK
I
2
C
Logic
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
56
55
54
53
52
51
50
49
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
PCI2
PCI_STP#
CPU_STP#
FS_C/TEST_SEL
REF
VSS_REF
XIN
XOUT
VDD_REF
SDATA
SCLK
VSS_CPU
CPUT0
CPUC0
VDD_CPU
CPUT1
CPUC1
IREF
VSSA
VDDA
CPUT2_ITP/SRCT7
CPUC2_ITP/SRCC7
VDD_SRC
CLKREQA#
CLKREQB#
SRCT5
SRCC5
VSS_SRC
56 TSSOP
CY28441
Rev 1.0, November 21, 2006
2200 Laurelwood Road, Santa Clara, CA 95054
Tel:(408) 855-0555
Fax:(408) 855-0550
Page 1 of 19
www.SpectraLinear.com
CY28441
Pin Description
Pin No.
33, 32
Name
CLKREQA#,
CLKREQB#,
CPU_STP#
CPUT2_ITP/SRCT7,
CPUC2_ITP/SRCC7
DOT96T, DOT96C
FS_A/USB_48
FS_B/TEST_MODE
Type
I, PU
Description
3.3V LVTTL input for enabling assigned SRC clock, active LOW.
CLKREQA#
defaults to enable/disable SRCT/C4, CLKREQB# defaults to enable/disable
SRCT/C5. Assignment can be changed via SMBUS register Byte 8.
3.3V LVTTL input for CPU_STP# active LOW.
54
36, 35
I, PU
44, 43, 41, 40 CPUT/C
O, DIF
Differential CPU clock outputs.
O, DIF
Selectable differential CPU or SRC clock output.
ITP_EN = 0 @ VTT_PWRGD# assertion = SRC7
ITP_EN = 1 @ VTT_PWRGD# assertion = CPU2
O, DIF
Fixed 96-MHz clock output.
I/O, SE
3.3V-tolerant input for CPU frequency selection/fixed 48-MHz clock output.
Refer to DC Electrical Specifications table for
V
IL_FS
,V
IH_FS
specifications.
I
3.3V-tolerant input for CPU frequency selection.
Selects Ref/N or Hi-Z when
in test mode
0 = Hi-Z, 1 = Ref/N
Refer to DC Electrical Specifications table for
V
IL_FS
,V
IH_FS
specifications.
3.3V-tolerant input for CPU frequency selection.
Selects test mode if pulled
to greater than 2.0V when VTT_PWRGD# is asserted low.
Refer to DC Electrical Specifications table for
V
IL_FS
,V
IH_FS
specifications.
A precision resistor is attached to this pin,
which is connected to the internal
current reference.
3.3V LVTTL input for PCI_STP# active LOW.
14, 15
12
16
53
FS_C/TEST_SEL
I
39
56, 3, 4, 5
55
8
9
52
46
47
26, 27
IREF
PCI
PCI_STP#
PCIF0/ITP_EN
PCIF1
REF
SCLK
SDATA
SRC4_SATAT,
SRC4_SATAC
I
O, SE
33 MHz clocks.
I, PU
I/O, SE
33-MHz clock/CPU2 select
(sampled on the VTT_PWRGD# assertion).
1 = CPU2_ITP, 0 = SRC7
O, SE
33 MHz clock.
O, SE
Reference clock.
3.3V 14.318-MHz clock output.
I
I/O
SMBus-compatible SCLOCK.
SMBus-compatible SDATA.
O, DIF
Differential serial reference clock.
Recommended output for SATA.
O, DIF
Differential serial reference clocks.
SRCT/C
24, 25, 22,
23, 19, 20,
17, 18, 31, 30
11
42
1,7
48
21, 28, 34
37
13
45
2,6
51
29
38
10
VDD_48
VDD_CPU
VDD_PCI
VDD_REF
VDD_SRC
VDDA
VSS_48
VSS_CPU
VSS_PCI
VSS_REF
VSS_SRC
VSSA
VTT_PWRGD#/PD
PWR
PWR
PWR
PWR
PWR
PWR
GND
GND
GND
GND
GND
GND
I
3.3V power supply for outputs.
3.3V power supply for outputs.
3.3V power supply for outputs.
3.3V power supply for outputs.
3.3V power supply for outputs.
3.3V power supply for PLL.
Ground for outputs.
Ground for outputs.
Ground for outputs.
Ground for outputs.
Ground for outputs.
Ground for PLL.
3.3V LVTTL input is a level sensitive strobe used to latch the USB_48/FS_A,
FS_B, FS_C/TEST_SEL and PCIF0/ITP_EN inputs.
After VTT_PWRGD#
(active LOW) assertion, this pin becomes a real-time input for asserting
power-down (active HIGH).
Rev 1.0, November 21, 2006
Page 2 of 19
CY28441
Pin Description
Pin No.
50
49
XIN
XOUT
Name
Type
I
14.318-MHz crystal input.
O, SE
14.318-MHz crystal output.
initialize to their default setting upon power-up, and therefore
use of this interface is optional. Clock device register changes
are normally made upon system initialization, if any are
required. The interface cannot be used during system
operation for power management functions.
Description
Frequency Select Pins (FS_A, FS_B and FS_C)
Host clock frequency selection is achieved by applying the
appropriate logic levels to FS_A, FS_B, FS_C inputs prior to
VTT_PWRGD# assertion (as seen by the clock synthesizer).
Upon VTT_PWRGD# being sampled LOW by the clock chip
(indicating processor VTT voltage is stable), the clock chip
samples the FS_A, FS_B and FS_C input values. For all logic
levels of FS_A, FS_B and FS_C, VTT_PWRGD# employs a
one-shot functionality in that once a valid low on
VTT_PWRGD# has been sampled, all further VTT_PWRGD#,
FS_A, FS_B and FS_C transitions will be ignored, except in
test mode. See
Table 1.
Data Protocol
The clock driver serial protocol accepts Byte Write, Byte Read,
Block Write, and Block Read operations from the controller.
For Block Write/Read operation, the bytes must be accessed
in sequential order from lowest to highest byte (most signif-
icant bit first) with the ability to stop after any complete byte
has been transferred. For Byte Write and Byte Read opera-
tions, the system controller can access individually indexed
bytes. The offset of the indexed byte is encoded in the
command code, as described in
Table 2.
The Block Write and Block Read protocol is outlined in
Table 3
while
Table 4
outlines the corresponding Byte Write and Byte
Read protocol. The slave receiver address is 11010010 (D2h).
Serial Data Interface
To enhance the flexibility and function of the clock synthesizer,
a two-signal serial interface is provided. Through the Serial
Data Interface, various device functions, such as individual
clock output buffers, can be individually enabled or disabled.
The registers associated with the Serial Data Interface
Table 1. Frequency Select Table FS_A, FS_B and FS_C
FS_C
1
0
0
0
0
1
1
1
FS_B
0
0
1
1
0
0
1
1
FS_A
1
1
1
0
0
0
0
1
CPU
100 MHz
133 MHz
SRC
100 MHz
100 MHz
PCIF/PCI
33 MHz
33 MHz
REF0
14.318 MHz
14.318 MHz
DOT96
96 MHz
96 MHz
USB
48 MHz
48 MHz
RESERVED
Table 2. Command Code Definition
Bit
7
(6:0)
Description
0 = Block Read or Block Write operation, 1 = Byte Read or Byte Write operation
Byte offset for Byte Read or Byte Write operation. For Block Read or Block Write operations, these bits should be
'0000000'
Table 3. Block Read and Block Write Protocol
Block Write Protocol
Bit
1
8:2
9
10
18:11
19
Start
Slave address – 7 bits
Write
Acknowledge from slave
Command Code – 8 bits
Acknowledge from slave
Description
Bit
1
8:2
9
10
18:11
19
Start
Slave address – 7 bits
Write
Acknowledge from slave
Command Code – 8 bits
Acknowledge from slave
Block Read Protocol
Description
Rev 1.0, November 21, 2006
Page 3 of 19
CY28441
Table 3. Block Read and Block Write Protocol
(continued)
Block Write Protocol
Bit
27:20
28
36:29
37
45:38
46
....
....
....
....
Byte Count – 8 bits
Acknowledge from slave
Data byte 1 – 8 bits
Acknowledge from slave
Data byte 2 – 8 bits
Acknowledge from slave
Data Byte /Slave Acknowledges
Data Byte N –8 bits
Acknowledge from slave
Stop
Description
Bit
20
27:21
28
29
37:30
38
46:39
47
55:48
56
....
....
....
....
Table 4. Byte Read and Byte Write Protocol
Byte Write Protocol
Bit
1
8:2
9
10
18:11
19
27:20
28
29
Start
Slave address – 7 bits
Write
Acknowledge from slave
Command Code – 8 bits
Acknowledge from slave
Data byte – 8 bits
Acknowledge from slave
Stop
Description
Bit
1
8:2
9
10
18:11
19
20
27:21
28
29
37:30
38
39
Start
Slave address – 7 bits
Write
Acknowledge from slave
Command Code – 8 bits
Acknowledge from slave
Repeated start
Slave address – 7 bits
Read
Acknowledge from slave
Data from slave – 8 bits
NOT Acknowledge
Stop
Byte Read Protocol
Description
Repeat start
Slave address – 7 bits
Read = 1
Acknowledge from slave
Byte Count from slave – 8 bits
Acknowledge
Data byte 1 from slave – 8 bits
Acknowledge
Data byte 2 from slave – 8 bits
Acknowledge
Data bytes from slave / Acknowledge
Data Byte N from slave – 8 bits
NOT Acknowledge
Stop
Block Read Protocol
Description
Control Registers
Byte 0:Control Register 0
Bit
7
6
5
4
3
@Pup
1
1
1
1
1
Name
CPUT2_ITP/SRCT7
CPUC2_ITP/SRCC7
RESERVED
SRC[T/C]5
SRC[T/C]4
SRC[T/C]3
Description
CPU[T/C]2_ITP/SRC[T/C]7 Output Enable
0 = Disable (Hi-Z), 1 = Enable
RESERVED
SRC[T/C]5 Output Enable
0 = Disable (Hi-Z), 1 = Enable
SRC[T/C]4 Output Enable
0 = Disable (Hi-Z), 1 = Enable
SRC[T/C]3 Output Enable
0 = Disable (Hi-Z), 1 = Enable
Rev 1.0, November 21, 2006
Page 4 of 19
CY28441
Byte 0:Control Register 0
(continued)
Bit
2
1
0
@Pup
1
1
1
Name
SRC[T/C]2
SRC[T/C]1
SRC[T/C]0
SRC[T/C]2 Output Enable
0 = Disable (Hi-Z), 1 = Enable
SRC[T/C]1 Output Enable
0 = Disable (Hi-Z), 1 = Enable
SRC[T/C]0 Output Enable
0 = Disable (Hi-Z), 1 = Enable
Description
Byte 1: Control Register 1
Bit
7
6
5
4
3
2
1
0
@Pup
1
1
1
1
0
1
1
0
Name
PCIF0
DOT_96T/C
USB_48
REF
Reserved
CPU[T/C]1
CPU[T/C]0
CPUT/C
SRCT/C
PCIF
PCI
PCIF0 Output Enable
0 = Disabled, 1 = Enabled
DOT_96 MHz Output Enable
0 = Disable (Hi-Z), 1 = Enabled
USB_48 MHz Output Enable
0 = Disabled, 1 = Enabled
REF Output Enable
0 = Disabled, 1 = Enabled
Reserved
CPU[T/C]1 Output Enable
0 = Disable (Hi-Z), 1 = Enabled
CPU[T/C]0 Output Enable
0 = Disable (Hi-Z), 1 = Enabled
Spread Spectrum Enable
0 = Spread off, 1 = Spread on
Description
Byte 2: Control Register 2
Bit
7
6
5
4
3
2
1
0
@Pup
1
1
1
1
1
1
1
1
Name
PCI5
PCI4
PCI3
PCI2
PCI
Reserved
Reserved
PCIF1
PCI5 Output Enable
0 = Disabled, 1 = Enabled
PCI4 Output Enable
0 = Disabled, 1 = Enabled
PCI3 Output Enable
0 = Disabled, 1 = Enabled
PCI2 Output Enable
0 = Disabled, 1 = Enabled
PCI Output Drive strength
0 = Low drive 1 = High drive
Reserved, Set = 1
Reserved, Set = 1
PCIF1 Output Enable
0 = Disabled, 1 = Enabled
Description
Byte 3: Control Register 3
Bit
7
6
5
@Pup
0
0
0
Name
SRC7
RESERVED
SRC5
Description
Allow control of SRC[T/C]7 with assertion of PCI_STP# or SW PCI_STP#
0 = Free running, 1 = Stopped with PCI_STP#
RESERVED
Allow control of SRC[T/C]5 with assertion of PCI_STP# or SW PCI_STP#
0 = Free running, 1 = Stopped with PCI_STP#
Rev 1.0, November 21, 2006
Page 5 of 19
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