6 page
PRELIMINARY
CY28323
Document #: 38-07004 Rev. *B
Page 6 of 22
Data Byte Configuration Map
Table 3. Byte Read and Byte Write Protocol
Byte Write Protocol
Byte Read Protocol
Bit
Description
Bit
Description
1
Start
1
Start
2:8
Slave address – 7 bits
2:8
Slave address – 7 bits
9
Write
9
Write
10
Acknowledge from slave
10
Acknowledge from slave
11:18
Command Code - 8 bits
‘1xxxxxxx’ stands for byte operation
bit[6:0] of the command code represents the off-
set of the byte to be accessed
11:18
Command Code - 8 bits
‘1xxxxxxx’ stands for byte operation
bit[6:0] of the command code represents the off-
set of the byte to be accessed
19
Acknowledge from slave
19
Acknowledge from slave
20:27
Data byte – 8 bits
20
Repeat start
28
Acknowledge from slave
21:27
Slave address – 7 bits
29
Stop
28
Read
29
Acknowledge from slave
30:37
Data byte from slave – 8 bits
38
Not Acknowledge
39
Stop
Data Byte 0
Bit
Pin#
Name
Description
Power On
Default
Bit 7
--
Spread Select2
‘000’ = OFF
‘001’ = Reserved
‘010’ = Reserved
‘011’ = Reserved
‘100’ = ±0.25%
‘101’ = –0.5%
‘110’ = ±0.5%
‘111’ = ±0.38%
0
Bit 6
--
Spread Select1
0
Bit 5
--
Spread Select0
0
Bit 4
--
SEL4
SW Frequency selection bits. See Table 4.0
Bit 3
--
SEL3
0
Bit 2
--
SEL2
0
Bit 1
--
SEL1
0
Bit 0
--
SEL0
0
Data Byte 1
Bit
Pin#
Name
Description
Power On
Default
Bit 7
38, 37
CPU1, CPU1#
(Active/Inactive)
1
Bit 6
41, 40
CPU0, CPU0#
(Active/Inactive)
1
Bit 5
22
48MHz
(Active/Inactive)
1
Bit 4
23
24_48MHz
(Active/Inactive)
1
Bit 3
27
3V66_3
(Active/Inactive)
1
