CYPRESS CY28346

CY28346
Clock Synthesizer with Differential CPU Outputs
Features
• 5/6 copies of 3V66 clocks
• SMBus support with read-back capabilities
• Spread Spectrum electromagnetic interference (EMI)
reduction
• Dial-a-Frequency™ features
• Dial-a-dB™ features
• 56-pin TSSOP and SSOP packages
• Compliant with Intel® CK 408 Mobile Clock Synthesizer
specifications
• 3.3V power supply
• Three differential CPU clocks
• Ten copies of PCI clocks
Table 1. Frequency Table[1]
CPU (0:2)
3V66
66BUFF(0:2)/
3V66(0:4)
66IN/3V66–5
PCI_FPCI
REF
USB/ DOT
0
66M
66M
66IN
66-MHz clock input
66IN/2
14.318M
48M
1
100M
66M
66IN
66-MHz clock input
66IN/2
14.318M
48M
S2
S1
S0
1
0
1
0
1
1
0
200M
66M
66IN
66-MHz clock input
66IN/2
14.318M
48M
1
1
1
133M
66M
66IN
66-MHZ clock input
66IN/2
14.318M
48M
0
0
0
66M
66M
66M
66M
33 M
14.318M
48M
0
0
1
100M
66M
66M
66M
33 M
14.318M
48M
0
1
0
200M
66M
66M
66M
33 M
14.318M
48M
0
1
1
133M
66M
66M
66M
33 M
14.318M
48M
M
0
0
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Hi-Z
M
0
1
TCLK/2
TCLK/4
TCLK/4
TCLK/4
TCLK/8
TCLK
TCLK/2
Block Diagram
Pin Configuration
XIN
XOUT
CPUT(0:2)
CPUC(0:2)
PLL1
CPU_STP#
IREF
VSSIREF
3V66_0
S(0:2)
VTT_PG#
/2
PCI_STP#
PCI(0:6)
PCI_F(0:2)
PLL2
48M USB
48M DOT
PD#
SDATA
SCLK
WD
Logic
I2C
Logic
66B[0:2]/3V66[2:4]
VDDA
Power
Up Logic
66IN/3V66-5
CY28346
3V66_1/VCH
MULT0
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
VDD
XIN
XOUT
VSS
PCIF0
PCIF1
PCIF2
VDD
VSS
PCI0
PCI1
PCI2
PCI3
VDD
VSS
PCI4
PCI5
PCI6
VDD
VSS
66B0/3V66_2
66B1/3V66_3
66B2/3V66_4
66IN/3V66_5
PD#
VDDA
VSSA
VTT_PG#
REF
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
REF
S1
S0
CPU_STP#
CPUT0
CPUC0
VDD
CPUT1
CPUC1
VSS
VDD
CPUT2
CPUC2
MULT0
IREF
VSSIREF
S2
48MUSB
48MDOT
VDD
VSS
3V66_1/VCH
PCI_STP#
3V66_0
VDD
VSS
SCLK
SDATA
Note:
1. TCLK is a test clock driven on the XTAL_IN input during test mode. M= driven to a level between 1.0V and 1.8V. If the S2 pin is at a M level during power-up, a
0 state will be latched into the device’s internal state register.
Cypress Semiconductor Corporation
Document #: 38-07331 Rev. *B
•
3901 North First Street
•
San Jose
•
CA 95134 • 408-943-2600
Revised December 26, 2002
CY28346
Pin Description
Pin
2
3
Name
XIN
XOUT
PWR
VDD
I/O
I
O
52, 51, 49, 48,
45, 44
10, 11, 12, 13,
16, 17, 18
5, 6, 7
CPUT(0:2),
CPUC(0:2)
PCI(0:6)
VDD
O
Description
Oscillator Buffer Input. Connect to a crystal or to an external clock.
Oscillator Buffer Output. Connect to a crystal. Do not connect when an external
clock is applied at XIN.
Differential Host Output Clock Pairs. See Table 1 for frequency/functionality.
VDDP
O
PCI Clock Outputs. Are synchronous to 66IN or 3V66 clock. See Table 1.
PCIF (0:2)
VDD
O
56
42
REF
IREF
VDD
VDD
O
I
28
VTT_PG#
VDD
I
39
38
33
35
48MUSB
48MDOT
3V66_0
3V66_1/VCH
VDD48
VDD48
VDD
VDD
O
O
O
O
25
PD#
VDD
I
PU
43
MULT0
33-MHz PCI Clocks. ÷2 copies of 66IN or 3V66 clocks that may be free running
(not stopped when PCI_STP# is asserted LOW) or may be stoppable depending
on the programming of SMBus register Byte3,Bits (3:5).
Buffered Output Copy of the Device’s XIN Clock.
Current Reference Programming Input for CPU Buffers. A resistor is
connected between this pin and VSSIREF.
Qualifying Input that Latches S(0:2) and MULT0. When this input is at a logic
LOW, the S(0:2) and MULT0 are latched.
Fixed 48-MHz USB Clock Outputs.
Fixed 48-MHZ DOT Clock Outputs.
3.3V 66-MHz Fixed-frequency Clock.
3.3V Clock Selectable with SMBus Byte0,Bit5, When Byte5,Bit5. When Byte
0,Bit 5 is at a logic 1, then this pin is a 48M output clock. When Byte0,Bit5 is a
logic 0, this is a 66M output clock (default).
Power-down Mode Pin. A logic LOW level causes the device to enter a
power-down state. All internal logic is turned off except for the SMBus logic. All
output buffers are stopped.
Programming Input Selection for CPU Clock Current Multiplier.
55, 54
29
S(0,1)
SDATA
I
I
30
40
SCLK
S2
I
VDD
34
PCI_STP#
VDD
53
CPU_STP#
VDD
24
66IN/3V66_5
VDD
21, 22, 23
66B(0:2)/
3V66(2:4)
VDD
VDD
1, 8, 14, 19, 32,
37, 46, 50
4, 9, 15, 20, 27,
31, 36, 47
41
26
VSSIREF
Document #: 38-07331 Rev. *B
Frequency Select Inputs. See Table 1.
Serial Data Input. Conforms to the SMBus specification of a Slave
Receive/Transmit device. It is an input when receiving data. It is an open drain
output when acknowledging or transmitting data.
I
Serial Clock Input. Conforms to the SMBus specification.
I
Frequency Select Input. See Table 1. This is a Tri-level input which is driven
T
HIGH, LOW or driven to a intermediate level.
I
PCI Clock Disable Input. When asserted LOW, PCI (0:6) clocks are synchroPU nously disabled in a LOW state. This pin does not effect PCIF (0:2) clocks’
outputs if they are programmed to be PCIF clocks via the device’s SMBus
interface.
I
CPU Clock Disable Input. When asserted LOW, CPUT (0:2) clocks are synchroPU nously disabled in a HIGH state and CPUC(0:2) clocks are synchronously
disabled in a LOW state.
I/O Input Connection for 66CLK(0:2) Output Clock Buffers if S2 = 1, or output
clock for fixed 66-MHz clock if S2 = 0. See Table 1.
O 3.3V Clock Outputs. These clocks are buffered copies of the 66IN clock or fixed
at 66 MHz. See Table 1.
PWR 3.3V Power Supply.
PWR Common Ground.
VSS
VDDA
I
PU
I
I
–
PWR Current Reference Programming Input for CPU Buffers. A resistor is
connected between this pin and IREF. This pin should also be returned to device
VSS.
PWR Analog Power Input. Used for phase-locked loops (PLLs) and internal analog
circuits. It is also specifically used to detect and determine when power is at an
acceptable level to enable the device to operate.
Page 2 of 20
CY28346
Two-Wire SMBus Control Interface
Serial Control Registers
The two-wire control interface implements a Read/Write slave
only interface according to SMBus specification.
Following the acknowledge of the Address Byte, two additional
bytes must be sent:
The device will accept data written to the D2 address and data
may read back from address D3. It will not respond to any other
addresses, and previously set control registers are retained as
long as power in maintained on the device.
1. “Command code“ byte
2. “Byte count” byte.
Although the data (bits) in the command is considered “don’t
care,” it must be sent and will be acknowledged. After the
Command Code and the Byte Count have been acknowledged, the sequence (Byte 0, Byte 1, and Byte 2) described
below will be valid and acknowledged.
Byte 0: CPU Clock Register[2,3]
Bit
@Pup
Pin#
7
0
Spread Spectrum Enable. 0 = Spread Off, 1 = Spread On
This is a Read and Write control bit.
6
0
CPU Clock Power-down Mode Select. 0 = Drive CPUT(0:2) to 4 or 6 IREF and drive CPUC(0:2)
LOW when PD# is asserted LOW. 1 = Tri-state all CPU outputs. This is only applicable when
PD# is LOW. It is not applicable to CPU_STP#.
5
0
4
Pin 53
44,45,48,49,5 CPU_STP#. Reflects the current value of the external CPU_STP# (pin 53) This bit is
1,52
Read-only.
3
Pin 34
10,11,12,13,1 Reflects the current value of the internal PCI_STP# function when read. Internally PCI_STP#
6,17,18
is a logical AND function of the internal SMBus register bit and the external PCI_STP# pin.
2
Pin 40
Frequency Select Bit 2. Reflects the value of SEL2 (pin 40). This bit is Read-only.
1
Pin 55
Frequency Select Bit 1. Reflects the value of SEL1 (pin 55). This bit is Read-only.
0
Pin 54
Frequency Select Bit 0. Reflects the value of SEL0 (pin 54). This bit is Read-only.
35
Description
3V66_1/VCH Frequency Select, 0 = 66M selected, 1 = 48M selected
This is a Read and Write control bit.
Byte 1: CPU Clock Register
Bit
@Pup
Pin#
Description
7
Pin 43
43
MULT0 (Pin 43) Value. This bit is Read-only.
6
0
53
CPUT/C(0:2) Output Functionality Control When CPU_STP# is Asserted. 0 = Drive
CPUT(0:2) to 4 or 6 IREF and drive CPUC(0:2) LOW when CPU_STP# asserted LOW.
1 = three-state all CPU outputs. This bit will override Byte0,Bit6 such that even if it is 0,
when PD# goes LOW the CPU outputs will be three-stated.
5
0
44,45
CPU2 Functionality Control When CPU_STP# is Asserted LOW. 1 = Free Running, 0 =
Stopped LOW with CPU_STP# asserted LOW. This is a Read and Write control bit.
4
0
48,49
CPU1 Functionality Control When CPU_STP# is Asserted LOW. 1 = Free Running, 0 =
Stopped LOW with CPU_STP# asserted LOW. This is a Read and Write control bit.
3
0
51,52
CPUT0 Functionality Control When CPU_STP# is Asserted LOW. 1 = Free Running, 0 =
Stopped LOW with CPU_STP# asserted LOW. This is a Read and Write control bit.
2
1
44,45
CPUT/C2 Output Control. 1 = enabled, 0 = disable HIGH and CPUC2 disables LOW. This
is a Read and Write control bit.
1
1
48,49
CPUT/C1 Output Control. 1 = enabled, 0 = disable HIGH and CPUC1 disables LOW. This
is a Read and Write control bit.
0
1
51,52
CPUT/C0 Output Control. 1 = enabled, 0 = disable HIGH and CPUC0 disables LOW. This
is a Read and Write control bit.
Notes:
2. PU = internal pull-up. PD = internal pull-down. T = tri-level logic input with valid logic voltages of LOW = < 0.8V, T = 1.0 – 1.8V and HIGH = > 2.0V.
3. The “Pin#” column lists the relevant pin number where applicable. The [email protected] column gives the default state at power-up.
Document #: 38-07331 Rev. *B
Page 3 of 20
CY28346
Byte 2: PCI Clock Control Register (all bits are Read and Write functional)
Bit
@Pup
Pin#
7
0
53
REF Output Control. 0 = high strength, 1 = low strength.
Description
6
1
18
PCI6 Output Control. 1 = enabled, 0 = forced LOW.
5
1
17
PCI5 Output Control. 1 = enabled, 0 = forced LOW.
4
1
16
PCI4 Output Control. 1 = enabled, 0 = forced LOW.
3
1
13
PCI3 Output Control. 1 = enabled, 0 = forced LOW.
2
1
12
PCI2 Output Control. 1 = enabled, 0 = forced LOW.
1
1
11
PCI1 Output Control. 1 = enabled, 0 = forced LOW.
0
1
10
PCI0 Output Control. 1 = enabled, 0 = forced LOW.
Byte 3: PCI_F Clock and 48M Control Register (all bits are Read and Write functional)
Bit
@Pup
Pin#
Description
7
1
38
48MDOT Output Control. 1 = enabled, 0 = forced LOW.
6
1
39
48MUSB Output Control. 1 = enabled, 0 = forced LOW.
5
0
7
PCI_STP#, Control of PCI_F2. 0 = Free Running, 1 = Stopped when PCI_STP# is LOW.
4
0
6
PCI_STP#, Control of PCI_F1. 0 = Free Running, 1 = Stopped when PCI_STP# is LOW.
3
0
5
PCI_STP#, Control of PCI_F0. 0 = Free Running, 1 = Stopped when PCI_STP# is LOW.
2
1
7
PCI_F2 Output Control. 1 = running, 0 = forced LOW.
1
1
6
PCI_F1 Output Control. 1 = running, 0 = forced LOW.
0
1
5
PCI_F0 Output Control. 1 = running, 0 = forced LOW.
Byte 4: DRCG Control Register (all bits are Read and Write functional)
Bit
@Pup
Pin#
Description
7
0
SS2 Spread Spectrum Control Bit (0 = down spread, 1 = center spread).
6
0
Reserved. Set = 0.
5
1
33
3V66_0 Output Enabled. 1 = enabled, 0 = disable.
4
1
35
3V66_1/VCH Output Enable. 1 = enabled, 0 = disabled.
3
1
24
3V66_5 Output Enable. 1 = enabled, 0 = disabled.
2
1
23
66B2/3V66_4 Output Enabled. 1 = enabled, 0 = disabled.
1
1
22
66B1/3V66_3 Output Enabled. 1 = enabled, 0 = disabled.
0
1
21
66B0/3V66_2 Output Enabled. 1 = enabled, 0 = disabled.
Byte 5: Clock Control Register (all bits are Read and Write functional)
Bit
@Pup
7
0
Pin#
SS1 Spread Spectrum Control Bit.
Description
6
1
SS0 Spread Spectrum Control Bit.
5
0
66IN to 66M delay Control MSB.
4
0
66IN to 66M delay Control LSB.
3
0
Reserved. Set = 0.
2
0
48MDOT Edge Rate Control. When set to 1, the edge is slowed by 15%.
1
0
Reserved. Set = 0.
0
0
USB edge rate control. When set to 1, the edge is slowed by 15%.
Document #: 38-07331 Rev. *B
Page 4 of 20
CY28346
Byte 6: Silicon Signature Register[4] (all bits are Read-only)
Bit
@Pup
7
0
6
0
5
0
4
1
3
0
2
0
1
1
0
1
Pin#
Description
Revision = 0001
Vendor Code = 0011
Byte 7: Reserved Register
Bit
@Pup
Pin#
Description
7
0
Reserved. Set = 0.
6
0
Reserved. Set = 0.
5
0
Reserved. Set = 0.
4
0
Reserved. Set = 0.
3
0
Reserved. Set = 0.
2
0
Reserved. Set = 0.
1
0
Reserved. Set = 0.
0
0
Reserved. Set = 0.
Byte 8: Dial-a-Frequency Control Register N
Bit
@Pup
Name
7
0
6
0
N6, MSB
5
0
N5
4
0
N4
3
0
N3
2
0
N2
1
0
N3
0
0
N0, LSB
Description
Reserved. Set = 0.
These bits are for programming the PLL’s internal N register. This access allows the user to
modify the CPU frequency at very high resolution (accuracy). All other synchronous clocks
(clocks that are generated from the same PLL, such as PCI) remain at their existing ratios
relative to the CPU clock.
Byte 9: Dial-a-Frequency Control Register R
Bit
@Pup
7
0
Name
Description
Reserved. Set = 0.
6
0
R5, MSB
5
0
R4
4
0
R3
3
0
R2
2
0
R1
1
0
R0
0
0
DAF_ENB
These bits are for programming the PLL’s internal R register. This access allows the user to
modify the CPU frequency at very high resolution (accuracy). All other synchronous clocks
(clocks that are generated from the same PLL, such as PCI) remain at their existing ratios
relative to the CPU clock.
R and N register mux selection. 0 = R and N values come from the ROM. 1 = data is loaded
from DAF (SMBus) registers.
Note:
4. When writing to this register, the device will acknowledge the Write operation, but the data itself will be ignored.
Document #: 38-07331 Rev. *B
Page 5 of 20
CY28346
P is a large-value PLL constant that depends on the frequency
selection achieved through the hardware selectors (S1, S0). P
value may be determined from Table 2.
any one point in this band to decrease in value. This technique
is achieved by modulating the clock away from its resting
frequency by a certain percentage (which also determines the
amount of EMI reduction). In this device, Spread Spectrum is
enabled by setting specific register bits in the SMBus control
bytes. Table 3 is a listing of the modes and percentages of
Spread Spectrum modulation that this device incorporates.
Table 2. P Value
Table 3. Spread Spectrum
Dial-a-Frequency Features
SMBus Dial-a-Frequency feature is available in this device via
Byte8 and Byte9.
S(1:0)
P
SS2
SS1
SS0
Spread Mode
Spread%
00
32005333
0
0
0
Down
+0.00, –0.25
01
48008000
0
0
1
Down
+0.00, –0.50
10
96016000
0
1
0
Down
+0.00, –0.75
64010667
0
1
1
Down
+0.00, –1.00
11
1
0
0
Center
+0.13, –0.13
Dial-a-dB Features
1
0
1
Center
+0.25, –0.25
SMBus Dial-a-dB feature is available in this device via Byte8
and Byte9.
1
1
0
Center
+0.37, –0.37
1
1
1
Center
+0.50, –1.50
Spread Spectrum Clock Generation (SSCG)
Test and Measurement Set-up
Spread Spectrum is a modulation technique used to
minimizing EMI radiation generated by repetitive digital
signals. A clock presents the greatest EMI energy at the center
frequency it is generating. Spread Spectrum distributes this
energy over a specific and controlled frequency bandwidth
therefore causing the average energy at
For Differential CPU Output Signals
T PC B
The following diagram shows lumped test load configurations
for the differential Host Clock Outputs.
33.2Ω
CPUT
M e asu rem en t P oint
2 pF
475Ω
M U LT S E L
33.2Ω
T PC B
CPUC
63.4Ω
M ea surem ent P o in t
2p F
63.4Ω
2 20Ω
Figure 1. 1.0V Test Load Termination
TPCB
33Ω
VDD
Measurement Point
CPUT
49.9Ω
2pF
MULTSEL
33Ω
TPCB
Measurement Point
CPUC
49.9Ω
2pF
475Ω
Figure 2. 0.7V Test Load Termination
Document #: 38-07331 Rev. *B
Page 6 of 20
CY28346
Output under Test
Probe
Load Cap
3.3V signals
tDC
-
-
3.3V
2.4V
1.5V
0.4V
0V
Tr
Tf
Figure 3. For Single-ended Output Signals
Buffer Characteristics
1. Output impedance of the current mode buffer circuit – Ro
(see Figure 4).
Current Mode CPU Clock Buffer Characteristics
2. Minimum and maximum required voltage operation range
of the circuit – Vop (see Figure 4).
The current mode output buffer detail and current reference
circuit details are contained in the previous table of this data
sheet. The following parameters are used to specify output
buffer characteristics:
3. Series resistance in the buffer circuit – Ros (see Figure 4).
4. Current accuracy at given configuration into nominal test
load for given configuration.
VDD3 (3.3V +/- 5%)
Slope ~ 1/R0
Ro
Iout
Ros
0V
1.2V
Iout
Vout = 1.2V max
Vout
Figure 4. Buffer Characteristics
Table 4. Host Clock (HCSL) Buffer Characteristics
Characteristic
Ro
Ros
Vout
Document #: 38-07331 Rev. *B
Min.
3000Ω (recommended)
Max.
N/A
N/A
1.2V
Page 7 of 20
CY28346
Iout is selectable depending on implementation. The parameters above apply to all configurations. Vout is the voltage at
the pin of the device.
The various output current configurations are shown in the
host swing select functions table. For all configurations, the
deviation from the expected output current is ±7% as shown in
the current accuracy table.
Table 5. CPU Clock Current Select Function
Mult0
Board Target Trace/Term Z
Reference R, Iref – Vdd (3*Rr)
Output Current
Voh @ Z
0
50Ω
Rr = 221 1%, Iref = 5.00mA
Ioh = 4*Iref
1.0V @ 50
1
50Ω
Rr = 475 1%, Iref = 2.32mA
Ioh = 6*Iref
0.7V @ 50
Table 6. Group Timing Relationship and Tolerances
Offset
Tolerance
3V66 to PCI
Description
2.5 ns
±1.0 ns
Conditions
48MUSB to 48MDOT Skew
0.0 ns
±1.0 ns
0 degrees phase shift
66B(0:2) to PCI offset
2.5 ns
±1.0 ns
66B Leads PCI (buffered mode)
3V66 Leads PCI (unbuffered mode)
USB and DOT 48M Phase Relationship
66B(0:2) to PCI Buffered Clock Skew
The 48MUSB and 48MDOT clocks are in phase. It is understood that the difference in edge rate will introduce some
inherent offset. When 3V66_1/VCH clock is configured for
VCH (48-MHz) operation it is also in phase with the USB and
DOT outputs. See Figure 5.
Figure 7 shows the difference (skew) between the 3V33(0:5)
outputs when the 66M clocks are connected to 66IN. This
offset is described in the Group Timing Relationship and Tolerances section of this data sheet. The measurements were
taken at 1.5V.
66IN to 66B(0:2) Buffered Prop Delay
3V66 to PCI Un-Buffered Clock Skew
The 66IN to 66B(0:2) output delay is shown in Figure 6.
Figure 8 shows the timing relationship between 3V66(0:5) and
PCI(0:6) and PCI_F(0:2) when configured to run in the unbuffered mode.
The Tpd is the prop delay from the input pin (66IN) to the
output pins (66B[0:2]). The outputs’ variation of Tpd is
described in the AC parameters section of this data sheet. The
measurement taken at 1.5V.
48MUSB
48MDOT
Figure 5. 48MUSB and 48MDOT Phase Relationship
66IN
Tpd
66B(0:2)
Figure 6. 66IN to 66B(0:2) Output Delay Figure
66B(0:2)
1.53.5ns
PCI(0:6)
PCIF(0:2)
Figure 7. Buffer Mode – 33V66(0:1); 66BUF(0:2) Phase Relationship
Document #: 38-07331 Rev. *B
Page 8 of 20
CY28346
Special Functions
CPU_STP# Clarification
PCI_F and IOAPIC Clock Outputs
The CPU_STP# signal is an active LOW input used to
synchronously stop and start the CPU output clocks while the
rest of the clock generator continues to function.
The PCIF clock outputs are intended to be used, if required,
for systems IOAPIC clock functionality. Any two of the PCI_F
clock outputs can be used as IOAPIC 33 Mhz clock outputs.
They are 3.3V outputs will be divided down via a simple
resistive voltage divider to meet specific system IOAPIC clock
voltage requirements. In the event that these clocks are not
required, they can be used as general PCI clocks or disabled
via the assertion of the PCI_STP# pin.
3V66_1/VCH Clock Output
The 3V66_1/VCH pin has a dual functionality that is selectable
via SMBus.
Configured as DRCG (66M), SMBus Byte0, Bit 5 = “0”
The default condition for this pin is to power-up in a 66M
operation. In 66M operation this output is SSCG-capable and
when spreading is turned on, this clock will be modulated.
Configured as VCH (48M), SMBus Byte0, Bit 5 = “1”
In this mode, output is configured as a 48-Mhz non-spread
spectrum output that is phase-aligned with other 48M outputs
(USB and DOT) to within 1 ns pin-to-pin skew. The switching
of 3V66_1/VCH into VCH mode occurs at system power-on.
When the SMBus Bit 5 of Byte 0 is programmed from a “0” to
a “1,” the 3V66_1/VCH output may glitch while transitioning to
48M output mode.
3V66(0:5)
CPU_STP# – Assertion
When CPU_STP# pin is asserted, all CPUT/C outputs that are
set with the SMBus configuration to be stoppable via assertion
of CPU_STP# will be stopped after being sampled by two
falling CPUT/C clock edges. The final state of the stopped
CPU signals is CPUT = HIGH and CPU0C = LOW. There is no
change to the output drive current values during the stopped
state. The CPUT is driven HIGH with a current value equal to
(Mult 0 “select”) × (Iref), and the CPUC signal will not be
driven. Due to external pull-down circuitry CPUC will be LOW
during this stopped state.
CPU_STP# Deassertion
The deassertion of the CPU_STP# signal will cause all
CPUT/C outputs that were stopped to resume normal
operation in a synchronous manner (meaning that no short or
stretched clock pulses will be produces when the clock
resumes). The maximum latency from the deassertion to
active outputs is no more than two CPUC clock cycles.
Three-state Control of CPU Clocks Clarification
During CPU_STP# and PD# modes, CPU clock outputs may
be set to driven or undriven (tri-state) by setting the corresponding SMBus entry in Bit6 of Byte0 and Bit6 of Byte1.
Tpci
PCI(0:6)
PCI_F(0:2)
Figure 8. Unbuffered Mode – 3V66(0:5) to PCI (0:6) and PCI_F(0:2) Phase Relationship
CPU_STP#
CPUT
CPUC
CPUT
CPUC
Figure 9. CPU_STP# Assertion Waveform
Document #: 38-07331 Rev. *B
Page 9 of 20
CY28346
PCI_STP# Assertion
The PCI_STP# signal is an active LOW input used for
synchronous stopping and starting the PCI outputs while the
rest of the clock generator continues to function. The set-up
time for capturing PCI_STP# going LOW is 10 ns (tsetup) (see
Figure 14.) The PCI_F (0:2) clocks will not be affected by this
pin if their control bits in the SMBus register are set to allow
them to be free running.
CPU_STP#
CPUT
CPUC
CPUT
CPUC
Figure 10. CPU_STP# Deassertion Waveform
Table 7. Cypress Clock Power Management Truth Table
B0b6
B1b6
PD#
CPU_STP#
Stoppable
CPUT
Stoppable
CPUC
0
0
1
1
Running
Running
Running
Running
0
0
1
0
Iref x6
Iref x6
Running
Running
0
0
0
1
Iref x2
LOW
Iref x2
LOW
0
0
0
0
Iref x2
LOW
Iref x2
LOW
0
1
1
1
Running
Running
Running
Running
0
1
1
0
Hi-Z
Hi-Z
Running
Running
0
1
0
1
Hi-Z
Hi-Z
Hi-Z
Hi-Z
0
1
0
0
Hi-Z
Hi-Z
Hi-Z
Hi-Z
1
0
1
1
Running
Running
Running
Running
1
0
1
0
Iref x6
Iref x6
Running
Running
1
0
0
1
Hi-Z
Hi-Z
Hi-Z
Hi-Z
1
0
0
0
Hi-Z
Hi-Z
Hi-Z
Hi-Z
1
1
1
1
Running
Running
Running
Running
1
1
1
0
Hi-Z
Hi-Z
Running
Running
1
1
0
1
Hi-Z
Hi-Z
Hi-Z
Hi-Z
1
1
0
0
Hi-Z
Hi-Z
Hi-Z
Hi-Z
Document #: 38-07331 Rev. *B
Non-Stop CPUT Non-Stop CPUC
Page 10 of 20
CY28346
PCI_STP# – Deassertion (transition from logic “0”
to logic “1”)
The deassertion of the PCI_STP# signal will cause all PCI(0:6)
and stoppable PCI_F(0:2) clocks to resume running in a
synchronous manner within two PCI clock periods after
PCI_STP# transitions to a HIGH level.
asynchronous function for powering up the system. When PD#
is LOW, all clocks are driven to a LOW value and held there
and the VCO and PLLs are also powered down. All clocks are
shut down in a synchronous manner so has not to cause
glitches while transitioning to the LOW “stopped” state.
PD# – Assertion
Note. The PCI STOP function is controlled by two inputs. One
is the device PCI_STP# pin number 34 and the other is SMBus
Byte 0,Bit 3. These two inputs to the function are logically
AND’ed. If either the external pin or the internal SMBus
register bit is set LOW, the stoppable PCI clocks will be
stopped in a logic LOW state. Reading SMBus Byte 0,Bit 3 will
return a 0 value if either of these control bits are set LOW
(which indicates that the devices stoppable PCI clocks are not
running).
When PD# is sampled LOW by two consecutive rising edges
of the CPUC clock, then on the next HIGH-to-LOW transition
of PCIF, the PCIF clock is stopped LOW. On the next
HIGH-to-LOW transition of 66Buff, the 66Buff clock is stopped
LOW. From this time, each clock will stop LOW on its next
HIGH-to-LOW transition, except the CPUT clock. The CPU
clocks are held with the CPUT clock pin driven HIGH with a
value of 2 × Iref, and CPUC undriven. After the last clock has
stopped, the rest of the generator will be shut down.
PD# (Power-down) Clarification
PD# – Deassertion
The PD# (power-down) pin is used to shut off all clocks prior
to shutting off power to the device. PD# is an asynchronous
active LOW input. This signal is synchronized internally to the
device powering down the clock synthesizer. PD# is an
The power-up latency between PD# rising to a valid logic ‘1’
level and the starting of all clocks is less than 3.0 ms.
t setup
PCI_STP#
PCI_F(0:2) 33M
PCI(0:6) 33M
Figure 11. PCI_STP# Assertion Waveform
t setup
PCI_STP#
PCI_F(0:2)
PCI(0:6)
Figure 12. PCI_STP# Deassertion Waveform
Document #: 38-07331 Rev. *B
Page 11 of 20
CY28346
66Buff[0..2]
PCIF
PW RDW N#
CPU 133MHz
CPU# 133MHz
3V66
66In
USB 48MHz
REF 14.318MHz
Figure 13. power-down Assertion Timing Waveforms Figure – Buffered Mode
PWRDWN#
CPUT(0:2) 133MHz
CPUC(0:2) 133MHz
PCI 33MHz
3V66
USB 48MHz
REF 14.318MHz
Figure 14. Power-down Assertion Timing Waveforms –Unbuffered Mode
Document #: 38-07331 Rev. *B
Page 12 of 20
CY28346
30uS min
400uS max
<1.8mS
66Buff1 / GMCH
66Buff[0,2]
PCIF / APIC
33MHz
PCI 33MHz
PW RDW N#
CPU 133MHz
CPU# 133MHz
3V66
66In
USB 48MHz
REF 14.318MHz
Figure 15. Power-down Deassertion Timing Waveforms – Buffered Mode
Table 8. PD# Functionality
PD#
DRCG
66CLK (0:2)
PCI_F/PCI
PCI
USB/DOT
1
66M
66Input
66Input/2
66Input/2
48M
0
LOW
LOW
LOW
LOW
LOW
Document #: 38-07331 Rev. *B
Page 13 of 20
CY28346
Maximum Ratings[5]
Storage Temperature:................................ –65°C to + 150°C
Operating Temperature:.................................... 0°C to +85°C
Input Voltage Relative to VSS:.............................. VSS – 0.3V
Maximum Power Supply:................................................ 3.5V
Input Voltage Relative to VDDQ or AVDD: ............. VDD + 0.3V
Current Accuracy[6]
Parameter
Iout
Conditions
VDD = nominal (3.30V)
Configuration
M0 = 0 or 1 and Rr (see Table 1)
Iout
VDD = 3.30 ± 5%
All combinations of M0 or 1 and Rr
(see Table 1)
Load
Nominal test load for given
configuration
Nominal test load for given
configuration
Min.
Max.
–7%
+ 7%
Inom Inom
–12% + 12%
Inom Inom
DC Parameters (VDD = VDDA = 3.3V ±5%, TA = 0°C to +70°C)
Parameter
Description
Conditions
IDD3.3V
Dynamic Supply Current
IPD3.3V
Power-down Supply Current
CIN
COUT
LPIN
Pin Inductance
CXTAL
Crystal Pin Capacitance
Min.
All frequencies at maximum values
Typ.
[7]
Max.
Unit
280
mA
Note 8
mA
Input Pin Capacitance
5
pF
Output Pin Capacitance
6
pF
7
nH
42
pF
PD# asserted
Measured from the XIN or XOUT pin to ground
30
36
AC Parameters (VDD = VDDA = 3.3V ±5%, TA = 0°C to +70°C)
66 MHz
Parameter
Description
Min.
Max.
100 MHz
Min.
Max.
133 MHz
Min.
Max.
200 MHz
Min.
Max.
Unit
Notes
Crystal
TDC
XIN Duty Cycle
47.5
52.5
47.5
52.5
47.5
52.5
47.5
52.5
%
9, 10, 11
TPERIOD
XIN period
69.84
71.0
69.84
71.0
69.84
71.0
69.84
71.0
ns
9, 12,
13, 10
VHIGH
XIN HIGH Voltage
0.7VDD
VDD
0.7VDD
VDD
0.7VDD
VDD
0.7VDD
VDD
V
VLOW
XIN LOW Voltage
0
0.3VDD
0
0.3VDD
0
0.3VDD
0
0.3VDD
V
TR / TF
XIN Rise and Fall Times
10.0
10.0
10.0
10.0
ns
14
TCCJ
XIN Cycle to Cycle Jitter
500
500
500
500
ps
12, 15,
10
CPU at 0.7V Timing
TDC
CPUT and CPUC Duty
Cycle
TPERIOD
CPUT and CPUC
Period
TSKEW
Any CPU to CPU Clock
Skew
45
55
45
55
45
55
45
55
%
15, 16,
19
14.85
15.3
9.85
10.2
7.35
7.65
4.85
5.1
ns
15, 16,
19
100
ps
12, 15,
16
100
100
100
Notes:
5. Multiple Supplies: The Voltage on any input or I/O pin cannot exceed the power pin during power-up. Power supply sequencing is NOT required.
6. Inom refers to the expected current based on the configuration of the device.
7. All outputs loaded as per maximum capacitive load table.
8. Absolute value = ((Programmed CPU Iref) × (2)) + 10 mA.
9. This parameter is measured as an average over 1 µs duration, with a crystal center frequency of 14.31818 MHz.
10. When Xin is driven from an external clock source.
11. This is required for the duty cycle on the REF clock out to be as specified. The device will operate reliably with input duty cycles up to 30/70 but the REF clock
duty cycle will not be within data sheet specifications.
12. All outputs loaded as perTable 9 below.
13. Probes are placed on the pins and measurements are acquired at 1.5V for 3.3V signals (see test and measurement set-up section of this data sheet).
14. Measured between 0.2VDD and 0.7VDD.
15. This measurement is applicable with Spread ON or Spread OFF.
16. Measured at crossing point (Vx) or where subtraction of CLK–CLK# crosses 0V Measured from VOL = 0.175V to VOH = 0.525V.
17. Measured from VOL = 0.175V to VOH = 0.525V.
18. Determined as a fraction of 2*(Trise–Tfall)/ (Trise+Tfall).
19. Test load is Rta = 33.2Ω, Rd = 49.9Ω .
Document #: 38-07331 Rev. *B
Page 14 of 20
CY28346
AC Parameters (VDD = VDDA = 3.3V ±5%, TA = 0°C to +70°C) (continued)
66 MHz
Parameter
Description
TCCJ
CPU Cycle to Cycle
Jitter
TR/TF
CPUT and CPUC Rise
and Fall Times
Min.
Max.
100 MHz
Min.
150
175
700
Max.
133 MHz
Min.
150
175
700
Max.
200 MHz
Min.
150
175
700
175
Max.
Unit
Notes
150
ps
15, 16,
19
700
ps
15, 17,
20
Rise/Fall Matching
20%
20%
20%
20%
DeltaTR
Rise Time Variation
125
125
125
125
DeltaTF
Fall Time Variation
VCROSS
Crossing Point Voltage
at 0.7V Swing
CPU at 1.0V Timing
TDC
CPUT and CPUC Duty
Cycle
125
125
125
17, 18,
19
ps
17, 19
125
ps
17, 19
280
430
280
430
280
430
280
430
mV
15, 19
45
55
45
55
45
55
45
55
%
15, 16
14.85
15.3
9.85
10.2
7.35
7.65
4.85
5.1
nS
15, 16
TPERIOD
CPUT and CPUC
Period
TSKEW
Any CPU to Any CPU
Clock Skew
100
100
100
100
pS
12, 15,
16
TCCJ
CPU Cycle to Cycle
Jitter
150
150
150
150
pS
12, 16
Differential
TR/TF
CPUT and CPUC Rise
and Fall Times
467
ps
15, 20
SE–
DeltaSlew
Absolute Single- ended
Rise/Fall Waveform
Symmetry
325
ps
21, 22
VCROSS
Cross Point at 1.0V
swing
760
mV
22
175
467
175
325
510
760
467
175
325
510
760
467
175
325
510
760
510
3V66
TDC
3V66 Duty Cycle
45
55
45
55
45
55
45
55
%
12, 13
TPERIOD
3V66 Period
15.0
15.3
15.0
15.3
15.0
15.3
15.0
15.3
ns
9, 12,
13
THIGH
3V66 HIGH Time
4.95
ns
23
TLOW
3V66 LOW Time
4.55
TR/TF
3V66 Rise and Fall
Times
0.5
TSKEW
Unbuffered
3V66 to 3V66 Clock
Skew
500
500
TSKEW
Buffered
3V66 to 3V66 Clock
Skew
250
TCCJ
DRCG Cycle to Cycle
Jitter
250
4.95
4.95
4.55
2.0
0.5
4.95
4.55
ns
24
2.0
ns
25
500
500
ps
12, 13
250
250
250
ps
12, 13
250
250
250
ps
12, 13
2.0
0.5
4.55
2.0
0.5
Notes:
20. Measurement taken from differential waveform, from –0.35V to +0.35V.
21. Measurements taken from common mode waveforms, measure rise/fall time from 0.41 to 0.86V. Rise/fall time matching is defined as “the instantaneous
difference between maximum CLK rise (fall) and minimum CLK# fall (rise) time or minimum CLK rise (fall) and maximum CLK# fall (rise) time.” This parameter
is designed form waveform symmetry.
22. Measured in absolute voltage, i.e., single-ended measurement.
23. THIGH is measured at 2.4V for non-host outputs.
24. TLOW is measured at 0.4V for all outputs.
25. Probes are placed on the pins, and measurements are acquired between 0.4V and 2.4V for 3.3V signals (see test and measurement set-up section of this data
sheet).
Document #: 38-07331 Rev. *B
Page 15 of 20
CY28346
AC Parameters (VDD = VDDA = 3.3V ±5%, TA = 0°C to +70°C) (continued)
66 MHz
Parameter
133 MHz
200 MHz
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
Unit
Notes
66B(0:2) Duty Cycle
45
55
45
55
45
55
45
55
%
12, 13
TR/TF
66B(0:2) Rise and Fall
Times
0.5
2.0
0.5
2.0
0.5
2.0
0.5
2.0
ns
12, 25
TSKEW
Any 66B to Any 66B
Skew
175
ps
12, 13
TPD
66IN to 66B(0:2) Propagation Delay
4.5
ns
12, 13
TCCJ
66B(0:2) Cycle to Cycle
Jitter
100
ps
12, 13,
26
55
%
12, 13
66B
TDC
PCI
TDC
Description
100 MHz
175
2.5
4.5
175
2.5
100
2.5
100
100
TPERIOD
PCI_F(0:2) PCI (0:6)
Period
30.0
30.0
30.0
30
nS
9, 12,
13
THIGH
PCI_F(0:2) PCI (0:6)
HIGH Time
12.0
12.0
12.0
12.0
nS
23
TLOW
PCI_F(0:2) PCI (0:6)
LOW Time
12.0
12.0
12.0
12.0
nS
24
TR/TF
PCI_F(0:2) PCI (0:6)
Rise and Fall Times
0.5
2.0
nS
25
TSKEW
Any PCI Clock to Any
PCI Clock Skew
500
500
500
500
pS
12, 13
TCCJ
PCI_F(0:2) PCI (0:6)
Cycle to Cycle Jitter
250
250
250
250
ps
12, 13
48MUSB Duty Cycle
TPERIOD
48MUSB Period
TR/TF
48MUSB Rise and Fall
Times
TCCJ
48MUSB Cycle to Cycle
Jitter
48MDOT
TDC
48MDOT Duty Cycle
TPERIOD
48MDOT Period
TR/TF
48MDOT Rise and Fall
Times
TCCJ
48MDOT Cycle to Cycle
Jitter
REF
TDC
REF Duty Cycle
TPERIOD
REF Period
TR/TF
REF Rise and Fall
Times
TCCJ
REF Cycle to Cycle
Jitter
45
55
0.5
45
55
2.5
45
2.0
45
4.5
PCI_F(0:2) PCI (0:6)
Duty Cycle
48MUSB
TDC
55
4.5
175
2.0
55
45
0.5
45
55
2.0
55
45
0.5
45
55
%
12, 13
ns
12, 13
2.10
ns
12, 25
350
ps
9, 12,
13
20.8299 20.8333 20.8299 20.8333 20.8299 20.8333 20.8299 20.8333
1.0
2.0
1.0
350
45
55
20.837
0.5
2.0
350
45
55
20.837
1.0
1.0
0.5
350
2.0
350
45
55
20.837
1.0
1.0
0.5
350
45
55
%
12, 13
ns
12, 13
1.0
ns
12, 13
350
ps
12, 13
20.837
1.0
0.5
350
45
55
45
55
45
55
45
55
%
12, 13
69.84
71.0
69.84
71.0
69.84
71.0
69.84
71.0
ns
12, 13
1.0
4.0
1.0
4.0
1.0
4.0
1.0
4.0
ns
12, 25
1000
ps
12, 13
1000
1000
1000
Note:
26. This figure is in addition to any jitter already present when the 66IN pin is being used as an input. Otherwise a 500-ps jitter figure is specified.
Document #: 38-07331 Rev. *B
Page 16 of 20
CY28346
AC Parameters (VDD = VDDA = 3.3V ±5%, TA = 0°C to +70°C) (continued)
66 MHz
Parameter
Description
100 MHz
133 MHz
200 MHz
Min.
Max.
Min.
Max.
Min.
Max.
Min.
Max.
Unit
Notes
TPZL/TPZH
Output Enable Delay
(All Outputs)
1.0
10.0
1.0
10.0
1.0
10.0
1.0
10.0
ns
10
TPZL/TPZH
Output disable delay (all
outputs)
1.0
10.0
1.0
10.0
1.0
10.0
1.0
10.0
ns
10
TSTABLE
All Clock Stabilization
from Power-up
3
ms
10
TSS
Stopclock Set-up Time
ns
27
TSH
Stopclock Hold Time
TSU
Oscillator Start-up Time
3
10.0
3
10.0
0
3
10.0
0
X
10.0
0
X
0
X
X
ns
27
ms
28
VID (0:3),
SEL (0,1)
VTT_PWRGD#
PWRGD
0.2-0.3mS
Delay
VDD Clock Gen
Clock State
Clock Outputs
Clock VCO
State 0
Wait for
VTT_GD#
State 1
Sample Sels
State 2
State 3
Off
On
(Note A)
On
Off
Figure 16. VTT_PWRGD# Timing
Table 9. Maximum Lumped Capacitive Output Loads
Clock
Max Load
Units
PCI Clocks
30
pF
3V66 (0,1)
30
pF
66B(0:2)
30
pF
48MUSB Clock
20
pF
48MDOT
10
pF
REF Clock
50
pF
Notes:
27. CPU_STP# and PCI _STP# set-up time with respect to any PCI_F clock to guarantee that the effected clock will stop or start at the next PCI_F clock’s rising edge
28. When crystal meets minimum 40Ω device series resistance specification.
29. Device is not affected, VTT_PWRGD# is ignored.
Document #: 38-07331 Rev. *B
Page 17 of 20
TP
W
= L RG
ow D #
CY28346
VT
S1
Delay 0.25mS
S2
Sample
Inputs (pins
54,55)
Enable Outputs
VDDA = 2.0V
S0
S3
Power Off
Normal
Operation
VDD3.3 = Off
Figure 17. Clock Generator Power-up/Run State Diagram
Ordering Information
Part Number
CY28346OC
CY28346OCT
CY28346ZC
CY28346ZCT
Package Type
56-pin SSOP – Tube
56-pin SSOP – Tape and Reel
56-pin TSSOP – Tube
56-pin TSSOP – Tape and Reel
Product Flow
Commercial, 0° to 70°C
Commercial, 0° to 70°C
Commercial, 0° to 70°C
Commercial, 0° to 70°C
Package Drawing and Dimensions
56-lead Shrunk Small Outline Package O56
51-85062-C
Document #: 38-07331 Rev. *B
Page 18 of 20
CY28346
56-lead Thin Shrunk Small Outline Package, Type II (6 mm × 12 mm) Z56
51-85060-B
Intel is a registered trademark of Intel Corporation. Dial-a-Frequency and Dial-a-dB are trademarks of Cypress Semiconductor.
All product and company names mentioned in this document may be the trademarks of their respective holders.
Document #: 38-07331 Rev. *B
Page 19 of 20
© Cypress Semiconductor Corporation, 2002. The information contained herein is subject to change without notice. Cypress Semiconductor Corporation assumes no responsibility for the use
of any circuitry other than circuitry embodied in a Cypress Semiconductor product. Nor does it convey or imply any license under patent or other rights. Cypress Semiconductor does not authorize
its products for use as critical components in life-support systems where a malfunction or failure may reasonably be expected to result in significant injury to the user. The inclusion of Cypress
Semiconductor products in life-support systems application implies that the manufacturer assumes all risk of such use and in doing so indemnifies Cypress Semiconductor against all charges.
CY28346
Document Title: CY28346 Clock Synthesizer with Differential CPU Outputs
Document Number: 38-07331
REV.
ECN NO.
Issue Date
Orig. of
Change
Description of Change
**
111653
02/21/02
DMG
New Data Sheet
*A
113983
03/08/02
DMG
Figure 14 changed
*B
122897
12/26/02
RBI
Document #: 38-07331 Rev. *B
Add power up requirements to maximum ratintgs information
Page 20 of 20