cy28445-5 SpectraLinear Inc, cy28445-5 Datasheet - Page 4

• Manufacturer Part Number: cy28445-5
• Description: Clock Generator For Intel Calistoga Chipset
• Manufacturer: SpectraLinear Inc

Rev 1.1, June 30, 2007
Data Protocol
The clock driver serial protocol accepts byte write, byte read,
block write, and block read operations from the controller. For
block write/read operation, the bytes must be accessed in
sequential order from lowest to highest byte (most significant
bit first) with the ability to stop after any complete byte has
been transferred. For byte write and byte read operations, the
Table 2. Command Code Definition
Table 3. Block Read and Block Write Protocol
27:20
36:29
45:38
18:11
(6:0)
8:2
Bit
Bit
10
19
28
37
46
....
....
....
....
1
9
7
Start
Slave address – 7 bits
Write
Acknowledge from slave
Command Code – 8 bits
Acknowledge from slave
Byte Count – 8 bits
(Skip this step if I
Acknowledge from slave
Data byte 1 – 8 bits
Acknowledge from slave
Data byte 2 – 8 bits
Acknowledge from slave
Data Byte /Slave Acknowledges
Data Byte N – 8 bits
Acknowledge from slave
Stop
0 = Block read or block write operation, 1 = Byte read or byte write operation
Byte offset for byte read or byte write operation. For block read or block write operations, these bits should be
'0000000'
Block Write Protocol
2
C_EN bit set)
Description
Description
system controller can access individually indexed bytes. The
offset of the indexed byte is encoded in the command code,
as described in Table 2.
The block write and block read protocol is outlined in Table 3
while Table 4 outlines the corresponding byte write and byte
read protocol. The slave receiver address is 11010010 (D2h).
27:21
37:30
46:39
55:48
18:11
8:2
Bit
38
10
19
20
28
29
47
56
....
....
....
....
1
9
Start
Slave address – 7 bits
Write
Acknowledge from slave
Command Code – 8 bits
Acknowledge from slave
Repeat start
Slave address – 7 bits
Read = 1
Acknowledge from slave
Acknowledge
Data byte 2 from slave – 8 bits
Acknowledge
Data bytes from slave / Acknowledge
Data Byte N from slave – 8 bits
NOT Acknowledge
Byte Count from slave – 8 bits
Data byte 1 from slave – 8 bits
Acknowledge
Stop
Block Read Protocol
Description
CY28445-5
Page 4 of 26