CY28378 Cypress Semiconductor, CY28378 Datasheet - Page 6

• Manufacturer Part Number: CY28378
• Description: FTG for Pentium 4 and Intel 845 Series Chipset
• Manufacturer: Cypress Semiconductor

Document #: 38-07519 Rev. **
Table 5. Byte Read and Byte Write Protocol
Byte Configuration Map
Byte 0
Byte 1
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
20:27
11:18
Bit
Bit
Bit
2:8
10
19
28
29
1
9
Start
Slave address – 7 bits
Write = 0
Acknowledge from slave
Command Code – 8 bits
'1xxxxxxx' stands for byte operation, bits[6:0] of
the command code represents the offset of the
byte to be accessed
Acknowledge from slave
Data byte from master – 8 bits
Acknowledge from slave
Stop
@Pup
@Pup
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
Byte Write Protocol
CPUT1, CPUC1
CPUT0, CPUC0
48MHz
24_48MHz
3V66_3
3V66_2
3V66_1
3V66_0
Spread Select2
Spread Select1
Spread Select0
SEL4
SEL3
SEL2
SEL1
SEL0
Description
Name
Name
(Active/Inactive)
(Active/Inactive)
(Active/Inactive)
(Active/Inactive)
(Active/Inactive)
(Active/Inactive)
(Active/Inactive)
‘000’ = OFF
‘001’ = +0.12, – 0.62%
‘010’ = +0.25, – 0.75%
‘011’ = +0.50, – 1.00%
‘100’ = ± 0.25%
‘101’ = +0.00, – 0.50%
‘110’ = ±0.5%
‘111’ = ±0.38%
SW Frequency selection bits. See Table 2.
11:18
21:27
30:37
Bit
2:8
10
19
20
28
29
38
39
1
9
Start
Slave address – 7 bits
Write = 0
Acknowledge from slave
Command Code – 8 bits
'1xxxxxxx' stands for byte operation, bits[6:0] of
the command code represents the offset of the
byte to be accessed
Acknowledge from slave
Repeat start
Slave address – 7 bits
Read = 1
Acknowledge from slave
Data byte from slave – 8 bits
Not Acknowledge
Stop
Description
Description
Byte Read Protocol
Description
CY28378
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