CY28312B-2T SPECTRALINEAR [SpectraLinear Inc], CY28312B-2T Datasheet - Page 3

• Manufacturer Part Number: CY28312B-2T
• Manufacturer: SPECTRALINEAR [SpectraLinear Inc]

Rev 1.0, November 21, 2006
Pin Definitions
Serial Data Interface
The CY28312B-2 features a two-pin, serial data interface that
can be used to configure internal register settings that control
particular device functions.
Data Protocol
The clock driver serial protocol supports byte/word write,
byte/word read, block write and block read operations from the
Table 1. Block Read and Block Write Protocol
SDATA
SCLK
VDD_CPU
VDDQ_AGP
VDDQ_PCI
VDDQ_48MHz
VDD_REF
VDD_Core
GND_REF,
GND_48MHz,
GND_PCI,
GND_AGP,
GND_Core,
GND_CPU
11:18
20:27
29:36
38:45
Bit
2:8
10
19
28
37
46
Pin Name
1
9
Start
Slave address – 7 bits
Write
Acknowledge from slave
Command Code – 8 bits
‘00000000’ stands for block operation
Acknowledge from slave
Byte Count – 8 bits
Acknowledge from slave
Data byte 0 – 8 bits
Acknowledge from slave
Data byte 1 – 8 bits
Acknowledge from slave
6:0
Bit
7
(continued)
Block Write Protocol
2, 8, 29, 32, 37,
Pin No.
15, 23
31
30
40
25
33
43
5
1
Description
0 = Block read or block write operation
1 = Byte/Word read or byte/word write operation
Byte offset for byte/word read or write operation. For block read or write operations, these bits
need to be set at ‘0000000’.
Type
Pin
I/O
G
P
P
P
P
P
P
I
Data pin for SMBus circuitry.
Clock pin for SMBus circuitry.
2.5V Power Connection. Power supply for CPU output buffers. Connect to
2.5V.
3.3V Power Connection. Power supply for AGP output buffers. Connect to 3.3V.
3.3V Power Connection. Power supply for PCI output buffers. Connect to 3.3V.
3.3V Power Connection. Power supply for 48-MHz output buffers. Connect to 3.3V.
3.3V Power Connection: Power supply for reference output buffers. Connect
to 3.3V.
3.3V Power Connection: Power supply for PLL core. Connect to 3.3V.
Ground Connections: Connect all ground pins to the common system ground
plane.
controller. For block write/read operation, the bytes must be
accessed in sequential order from lowest to highest byte with
the ability to stop after any complete byte has been trans-
ferred. For byte/word write and byte read operations, system
controller can access individual indexed byte. The offset of the
indexed byte is encoded in the command code.
The definition for the command code is defined in Table 1.
11:18
21:27
30:37
Bit
2:8
10
19
20
28
29
38
1
9
Descriptions
Start
Slave address – 7 bits
Write
Acknowledge from slave
Command Code – 8 bits
‘00000000’ stands for block operation
Acknowledge from slave
Repeat start
Slave address – 7 bits
Read
Acknowledge from slave
Byte count from slave – 8 bits
Acknowledge
Pin Description
Block Read Protocol
Description
CY28312B-2
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