
CY28446
.......................Document #: 001-00168 Rev *F Page 5 of 19
Control Registers
Table 5. Byte Read and Byte Write Protocol
Byte Write Protocol
Byte Read Protocol
Bit
Description
Bit
Description
1Start
8:2
Slave address–7 bits
8:2
Slave address–7 bits
9Write
10
Acknowledge from slave
10
Acknowledge from slave
18:11
Command Code–8 bits
18:11
Command Code–8 bits
19
Acknowledge from slave
19
Acknowledge from slave
27:20
Data byte–8 bits
20
Repeated start
28
Acknowledge from slave
27:21
Slave address–7 bits
29
Stop
28
Read
29
Acknowledge from slave
37:30
Data from slave–8 bits
38
NOT Acknowledge
39
Stop
Byte 0: Control Register 0
Bit
@Pup
Name
Description
7
1
CPU2_ITP[T/C]/SRC7[T/C] CPU2_ITP[T/C]/SRC[T/C]7 Output Enable
0 = Disable (Tri-state), 1 = Enable
6
1
SRC[T/C]6
SRC[T/C]6 Output Enable
0 = Disable (Tri-state), 1 = Enable
5
1
SRC[T/C]5
SRC[T/C]5 Output Enable
0 = Disable (Tri-state), 1 = Enable
4
1
Reserved
3
1
SRC[T/C]3
SRC[T/C]3 Output Enable
0 = Disable (Tri-state), 1 = Enable
2
1
SRC[T/C]2
SRC[T/C]2 Output Enable
0 = Disable (Tri-state), 1 = Enable
1
SRC[T/C]1
SRC[T/C]1 Output Enable
0 = Disable (Tri-state), 1 = Enable
0
1
SRC[T/C]0
SRC[T/C]0 Output Enable
0 = Disable (Tri-state), 1 = Enable
Byte 1: Control Register 1
Bit
@Pup
Name
Description
7
1
PCIF0
PCIF0 Output Enable
0 = Disable, 1 = Enable
6
1
DOT_96[T/C]
DOT_96 MHz Output Enable
0 = Disable (Tri-state), 1 = Enable
5
1
USB_48
USB_48 Output Enable
0 = Disable, 1 = Enable
4
1
REF
REF Output Enable
0 = Disable, 1 = Enable
3
1
Reserved
2
1
CPU[T/C]1
CPU[T/C]1 Output Enable
0 = Disable (Tri-state), 1 = Enable
1
CPU[T/C]0
CPU[T/C]0 Output Enable
0 = Disable (Tri-state), 1 = Enable