CY28301 Cypress Semiconductor, CY28301 Datasheet - Page 3

• Manufacturer Part Number: CY28301
• Description: Frequency Generator for Intel Integrated Chipset
• Manufacturer: Cypress Semiconductor

Serial Data Interface
The CY28301 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
Table 1. Command Code Definition
Table 2. Block Read and Block Write Protocol
Document #: 38-07011 Rev. *C
11:18
20:27
29:36
38:45
Bit
2:8
10
19
28
37
46
...
...
...
...
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
Data byte N/Slave acknowledge...
Data byte N – 8 bits
Acknowledge from slave
Stop
Bit
6:0
7
Block Write Protocol
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.’
the 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, the
system controller can access individual indexed bytes. The
offset of the indexed byte is encoded in the command code.
The definition for the command code is defined as follows.
11:18
21:27
30:37
39:46
48:55
2:8
Bit
20
28
47
10
19
29
38
56
...
...
...
...
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
Data byte from slave – 8 bits
Acknowledge
Data byte from slave – 8 bits
Acknowledge
Data bytes from slave/acknowledge
Data byte N from slave – 8 bits
Not acknowledge
Stop
Block Read Protocol
Description
CY28301
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