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PCK2057DGG Datasheet PDF : 13 Pages
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Philips Semiconductors
70 – 190 MHz I2C differential 1:10 clock driver
Product data
PCK2057
I2C ADDRESS
1 1 0 1 0 0 1 R/W
su01394
I2C CONSIDERATIONS
I2C has been chosen as the serial bus interface to control the PCK2057. I2C was chosen to support the JEDEC proposal JC-42.5 168 Pin
Unbuffered SDRAM DIMM. All vendors are required to determine the legal issues associated with the manufacture of I2C devices.
1) Address assignment: The clock driver in this specification uses the single, 7-bit address shown below. All devices can use the address if only
one master clock driver is used in a design. The address can be re-used for the CKBF device if no other conflicting I2C clock driver is used in
the system.
The following address was confirmed by Philips on 09/04/96.
A6
A5
A4
A3
A2
A1
A0
R/W
1
1
0
1
0
0
1
0
NOTE: The R/W bit is used by the I2C controller as a data direction bit. A ‘zero’ indicates a transmission (WRITE) to the clock device. A ‘one’
indicates a request for data (READ) from the clock driver. Since the definition of the clock buffer only allows the controller to WRITE data; the
R/W bit of the address will always be seen as ‘zero’. Optimal address decoding of this bit is left to the vendor.
2) Data Transfer Rate: 100 kbits/s (standard mode) is the base functionality required. Fast mode (400 kbits/s) functionality is optional.
3) Logic Levels: I2C logic levels are based on a percentage of VDD for the controller and other devices on the bus. Assume all devices are
based on a 3.3 Volt supply.
4) Data Byte Format: Byte format is 8 Bits as described in the following appendices.
5) Data Protocol: To simplify the clock I2C interface, the clock driver serial protocol was specified to use only block writes from the controller.
The bytes must be accessed in sequential order from lowest to highest byte with the ability to stop after any complete byte has been
transferred. Indexed bytes are not allowed. However, the SMBus controller has a more specific format than the generic I2C protocol.
The clock driver must meet this protocol which is more rigorous than previously stated I2C protocol. Treat the description from the viewpoint of
controller. The controller “writes” to the clock driver.
1 bit
7 bits
1
1
8 bits
1
1 bit
8 bits
1
8 bits
1
1
Start bit
Slave Address R/W Ack
DUMMY
Ack
DUMMY
Ack Data Byte 1 Ack Data Byte 2 Ack Stop
NOTE: The acknowledgement bit is returned by the slave/receiver (the clock driver).
SW00911
6) Electrical Characteristics: All electrical characteristics must meet the standard mode specifications found in section 15 of the I2C
specification.
a) Pull-Up Resistors: Any internal resistors pull-ups on the SDATA and SCLOCK inputs must be stated in the individual datasheet. The use of
internal pull-ups on these pins of below 100 kΩ is discouraged. Assume that the board designer will use a single external pull-up resistor for
each line and that these values are in the 5–6 kΩ range. Assume one I2C device per DIMM (serial presence detect), one I2C controller, one
clock driver plus one/two more I2C devices on the platform for capacitive loading purposes.
(b) Input Glitch Filters: Only fast mode I2C devices require input glitch filters to suppress bus noise. The clock driver is specified as a standard
mode device and is not required to support this feature.
For specific I2C information, consult the Philips I2C Peripherals Data Handbook IC12 (1997).
2001 Jun 12
4
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