CYPRESS W40S11

W40S11-23
Clock Buffer/Driver
Features
Key Specifications
• Thirteen skew-controlled CMOS clock outputs
(SDRAM0:12)
• Supports three SDRAM DIMMs
• Ideal for high-performance systems designed around
Intel’s latest chip set
• I2C serial configuration interface
• Clock Skew between any two outputs is less than 250 ps
• 1- to 5-ns propagation delay
• DC to 133-MHz operation
• Single 3.3V supply voltage
• Low power CMOS design packaged in a 28-pin, 300-mil
SOIC (Small Outline Integrated Circuit)
Overview
Supply Voltages:........................................... VDD = 3.3V±5%
Operating Temperature:.................................... 0°C to +70°C
Input Threshold: .................................................. 1.5V typical
Maximum Input Voltage: .......................................VDD + 0.5V
Input Frequency:............................................... 0 to 133 MHz
BUF_IN to SDRAM0:12 Propagation Delay: ...... 1.0 to 5.0 ns
Output Edge Rate:..............................................
>1.5 V/ns
Output Clock Skew: .................................................. ±250 ps
Output Duty Cycle: .................................. 45/55% worst case
Output Impedance: ...............................................15Ω typical
Output Type: ................................................ CMOS rail-to-rail
The Cypress W40S11-23 is a low-voltage, thirteen-output
clock buffer. Output buffer impedance is approximately 15Ω,
which is ideal for driving SDRAM DIMMs.
Pin Configuration
Block Diagram
SDATA
SCLOCK
Serial Port
SOIC
Device Control
SDRAM0
SDRAM1
SDRAM2
SDRAM3
SDRAM4
SDRAM5
SDRAM6
SDRAM7
SDRAM8
BUF_IN
VDD
SDRAM0
SDRAM1
GND
VDD
SDRAM2
SDRAM3
GND
BUF_IN
SDRAM4
SDRAM5
SDRAM12
VDD
SDATA[1]
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VDD
SDRAM11
SDRAM10
GND
VDD
SDRAM9
SDRAM8
GND
VDD
SDRAM7
SDRAM6
GND
GND
[1]
SCLOCK
SDRAM9
SDRAM10
SDRAM11
Note:
1. Internal pull-up resistor of 250K on SDATA and SCLOCK inputs
(not CMOS level).
SDRAM12
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134 •
408-943-2600
September 28, 1999 rev. **
W40S11-23
Pin Definitions
Pin
No.
Pin
Type
2, 3, 6, 7, 10,
11, 18, 19,
22, 23, 26,
27, 12
O
SDRAM Outputs: Provides buffered copy of BUF_IN. The propagation delay from a
rising input edge to a rising output edge is 1 to 5 ns. All outputs are skew controlled to
within ± 250 ps of each other.
BUF_IN
9
I
Clock Input: This clock input has an input threshold voltage of 1.5V (typ).
SDATA
14
I/O
I2C Data input: Data should be presented to this input as described in the I2C section
of this data sheet. Internal 250-kΩ pull-up resistor.
SCLOCK
15
I
I2C clock input: The I2C data clock should be presented to this input as described in
the I2C section of this data sheet. Internal 250-kΩ pull-up resistor.
VDD
1, 5, 13, 20,
24, 28
P
Power Connection: Power supply for core logic and output buffers. Connected to 3.3V
supply.
GND
4, 8, 16, 17,
21, 25
G
Ground Connection: Connect all ground pins to the common system ground plane.
Pin Name
SDRAM0:12
Pin Description
Functional Description
capacitive load. Thus, output signaling is both TTL and CMOS
level compatible. Nominal output buffer impedance is 15Ω.
Output Drivers
Operation
The W40S11-23 output buffers are CMOS type which deliver
a rail-to-rail (GND to VDD) output voltage swing into a nominal
Data is written to the W40S11-23 in ten bytes of eight bits
each. Bytes are written in the order shown in Table 1.
Table 1. Byte Writing Sequence
Byte
Sequence
Byte Name
1
Slave Address
11010010
Commands the W40S11-23 to accept the bits in Data Bytes 0–6 for internal register configuration. Since other devices may exist on the same
common serial data bus, it is necessary to have a specific slave address
for each potential receiver. The slave receiver address for the W40S11-23
is 11010010. Register setting will not be made if the Slave Address is not
correct (or is for an alternate slave receiver).
2
Command
Code
Don’t Care
Unused by the W40S11-23, therefore bit values are ignored (don’t care).
This byte must be included in the data write sequence to maintain proper
byte allocation. The Command Code Byte is part of the standard serial
communication protocol and may be used when writing to another addressed slave receiver on the serial data bus.
3
Byte Count
Don’t Care
Unused by the W40S11-23, therefore bit values are ignored (don’t care).
This byte must be included in the data write sequence to maintain proper
byte allocation. The Byte Count Byte is part of the standard serial communication protocol and may be used when writing to another addressed
slave receiver on the serial data bus.
4
Data Byte 0
Refer to Table 2
5
Data Byte 1
6
Data Byte 2
The data bits in these bytes set internal W40S11-23 registers that control
device operation. The data bits are only accepted when the Address Byte
bit sequence is 11010010, as noted above. For description of bit control
functions, refer to Table 2, Data Byte Serial Configuration Map.
7
Data Byte 3
Don’t Care
Refer to Cypress Frequency Timing Generators.
8
Data Byte 4
9
Data Byte 5
10
Data Byte 6
Bit Sequence
Byte Description
2
W40S11-23
Writing Data Bytes
Table 2 gives the bit formats for registers located in Data Bytes
0–6.
Each bit in the data bytes control a particular device function.
Bits are written MSB (most significant bit) first, which is bit 7.
Table 2. Data Bytes 0–2 Serial Configuration Map[2]
Affected Pin
Bit(s)
Pin No.
Pin Name
Bit Control
Control Function
0
1
Data Byte 0 SDRAM Active/Inactive Register (1=Enable, 0=Disable)
7
11
SDRAM5
Clock Output Disable
Low
Active
6
10
SDRAM4
Clock Output Disable
Low
Active
5
N/A
Reserved
(Reserved)
-
-
4
N/A
Reserved
(Reserved)
-
-
3
7
SDRAM3
Clock Output Disable
Low
Active
2
6
SDRAM2
Clock Output Disable
Low
Active
1
3
SDRAM1
Clock Output Disable
Low
Active
0
2
SDRAM0
Clock Output Disable
Low
Active
Data Byte 1 SDRAM Active/Inactive Register (1=Enable, 0=Disable)
7
27
SDRAM11
Clock Output Disable
Low
Active
6
26
SDRAM10
Clock Output Disable
Low
Active
5
23
SDRAM9
Clock Output Disable
Low
Active
4
22
SDRAM8
Clock Output Disable
Low
Active
3
N/A
Reserved
(Reserved)
-
-
2
N/A
Reserved
(Reserved)
-
-
1
19
SDRAM7
Clock Output Disable
Low
Active
0
18
SDRAM6
Clock Output Disable
Low
Active
-
-
Low
Active
Data Byte 2 SDRAM Active/Inactive Register (1=Enable, 0=Disable)
7
N/A
Reserved
(Reserved)
6
12
SDRAM12
Clock Output Disable
5
N/A
Reserved
(Reserved)
--
--
4
N/A
Reserved
(Reserved)
--
--
3
N/A
Reserved
(Reserved)
--
--
2
N/A
Reserved
(Reserved)
--
--
1
N/A
Reserved
(Reserved)
--
--
0
N/A
Reserved
(Reserved)
--
--
Note:
2. At power-up all SDRAM outputs are enabled and active. Program Reserved bits to a “0.”
3
W40S11-23
How To Use the Serial Data Interface
logic 1. All bus devices generally have logic inputs to receive
data.
Electrical Requirements
Although the W40S11-23 is a receive-only device (no data
write-back capability), it does transmit an “acknowledge” data
pulse after each byte is received. Thus, the SDATA line can
both transmit and receive data.
Figure 1 illustrates electrical characteristics for the serial interface bus used with the W40S11-23. Devices send data over
the bus with an open drain logic output that can (a) pull the bus
line LOW, or (b) let the bus default to logic 1. The pull-up resistor on the bus (both clock and data lines) establish a default
The pull-up resistor should be sized to meet the rise and fall
times specified in AC parameters, taking into consideration total bus line capacitance.
VDD
VDD
~ 2kΩ
~ 2kΩ
SERIAL BUS DATA LINE
SERIAL BUS CLOCK LINE
SDCLK
CLOCK IN
CLOCK OUT
SDATA
SCLOCK
DATA IN
N
DATA OUT
CLOCK IN
N
DATA IN
DATA OUT
CHIP SET
(SERIAL BUS MASTER TRANSMITTER)
CLOCK DEVICE
(SERIAL BUS SLAVE RECEIVER)
Figure 1. Serial Interface Bus Electrical Characteristics
4
SDATA
N
W40S11-23
Signaling Requirements
A write sequence is initiated by a “start bit” as shown in Figure
3. A “stop bit” signifies that a transmission has ended.
As shown in Figure 2, valid data bits are defined as stable logic
0 or 1 condition on the data line during a clock HIGH (logic 1)
pulse. A transitioning data line during a clock HIGH pulse may
be interpreted as a start or stop pulse (it will be interpreted as
a start or stop pulse if the start/stop timing parameters are
met).
As stated previously, the W40S11-23 sends an “acknowledge”
pulse after receiving eight data bits in each byte as shown in
Figure 4.
SDATA
SCLOCK
Valid
Data
Bit
Change
of Data Allowed
Figure 2. Serial Data Bus Valid Data Bit
SDATA
SCLOCK
Start
Bit
Stop
Bit
Figure 3. Serial Data Bus Start and Stop Bit
5
Figure 4. Serial Data Bus Write Sequence
Signaling from System Core Logic
Start Condition
Stop Condition
Slave Address
(First Byte)
Command Code
(Second Byte)
SDATA
MSB
1
1
0
1
0
0
1
LSB
0
SCLOCK
1
2
3
4
5
6
7
8
Byte Count
(Third Byte)
MSB
A
1
LSB
2
3
4
5
6
7
8
Last Data Byte
(Last Byte)
MSB
A
1
MSB
2
3
4
1
LSB
2
3
4
5
6
7
8
A
SDATA
Acknowledgment Bit
from Clock Device
Signaling by Clock Device
6
tSPF
tLOW
SCLOCK
tSTHD
tDSU
tHIGH
tR
tF
tDHD
tSP
tSPSU
tSTHD
t SPSU
W40S11-23
Figure 5. Serial Data Bus Timing Diagram
SDATA
W40S11-23
Absolute Maximum Ratings
above those specified in the operating sections of this specification is not implied. Maximum conditions for extended periods may affect reliability
Stresses greater than those listed in this table may cause permanent damage to the device. These represent a stress rating
only. Operation of the device at these or any other conditions
Parameter
Description
Rating
Unit
V
VDD, VIN
Voltage on any pin with respect to GND
–0.5 to +7.0
–65 to +150
°C
0 to +70
°C
–55 to +125
°C
TSTG
Storage Temperature
TA
Operating Temperature
TB
Ambient Temperature under Bias
DC Electrical Characteristics: TA = 0°C to +70°C, VDD = 3.3V±5%
Parameter
IDD
Description
3.3V Supply Current
Test Condition/Comments
Min
Typ
BUF_IN = 100 MHz
Max
Unit
250
mA
V
Logic Inputs
VIL
Input Low Voltage
GND–0.3
0.8
VIH
Input High Voltage
2.0
VDD+0.5
V
IILEAK
Input Leakage Current, BUF_IN
–5
+5
µA
IILEAK
Input Leakage Current[3]
–20
+5
µA
50
mV
Logic Outputs (SDRAM0:12)
VOL
Output Low Voltage
IOL = 1 mA
VOH
Output High Voltage
IOH = –1 mA
3.1
IOL
Output Low Current
VOL = 1.5V
65
100
160
mA
IOH
Output High Current
VOH = 1.5V
70
110
185
mA
V
Pin Capacitance/Inductance
CIN
Input Pin Capacitance
5
pF
COUT
Output Pin Capacitance
6
pF
LIN
Input Pin Inductance
7
nH
Note:
3. SDATA and SCLOCK logic pins have 250-kΩ internal pull-up resistors.
7
W40S11-23
AC Electrical Characteristics: TA = 0°C to +70°C, VDD = 3.3V±5% (Lump Capacitance Test Load = 30 pF)
Parameter
Description
Test Condition
Min
Typ
Max
Unit
fIN
Input Frequency
0
133
MHz
tR
Output Rise Edge Rate
Measured from 0.4V to 2.4V
1.5
4.0
V/ns
tF
Output Fall Edge Rate
Measured from 2.4V to 0.4V
1.5
4.0
V/ns
tSR
Output Skew, Rising Edges
250
ps
tSF
Output Skew, Falling Edges
250
ps
tEN
Output Enable Time
1.0
8.0
ns
tDIS
Output Disable Time
1.0
8.0
ns
tPR
Rising Edge Propagation Delay
1.0
5.0
ns
tPF
Falling Edge Propagation Delay
1.0
5.0
ns
tD
Duty Cycle
45
55
%
Zo
AC Output Impedance
tPR
Rising Edge Propagation Delay
Measured at 1.5V
1.0
Ordering Information
Ordering Code
W40S11
Ω
15
Freq. Mask
Code
Package
Name
-23
G
Package Type
28-pin SOIC (300 mils)
Document #: 38-00793
8
5.0
ns
W40S11-23
Package Diagram
28-Pin Small Outline Integrated Circuit (SOIC, 0.300 inch)
© Cypress Semiconductor Corporation, 1999. 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.