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CY28317-2
Document #: 38-07094 Rev. *B
Page 11 of 21
Byte 14: Programmable Frequency Select M-Value Register
Bit
Name
Default
Description
Bit 7
Pro_Freq_EN
0
Programmable output frequencies enabled
0 = Disabled
1 = Enabled
Bit 6
CPU_FSEL_M6
0
If Prog_Freq_EN is set, CY28317-2 will use the values programmed in
CPU_FSEL_N[7:0] and CPU_FSEL_M[6:0] to determine the CPU output fre-
quency. The new frequency will start to load whenever CPU_FSELM[6:0] is
updated.
The setting of the FS_Override bit determines the frequency ratio for CPU,
SDRAM and PCI. When it is cleared, CY28317-2 will use the same frequency
ratio stated in the Latched FS[4:0] register. When it is set, CY28317-2 will use
the frequency ratio stated in the SEL[4:0] register.
CY28317-2 supports programmable CPU frequencies ranging from 50 MHz
to 248 MHz.
Bit 5
CPU_FSEL_M5
0
Bit 4
CPU_FSEL_M4
0
Bit 3
CPU_FSEL_M3
0
Bit 2
CPU_FSEL_M2
0
Bit 1
CPU_FSEL_M1
0
Bit 0
CPU_FSEL_M0
0
Byte 15: Reserved Register
Bit
Pin#
Name
Default
Description
Bit 7
–
Reserved
0
Reserved
Bit 6
–
Reserved
0
Reserved
Bit 5
–
Reserved
0
Reserved
Bit 4
–
Reserved
0
Reserved
Bit 3
–
Reserved
0
Reserved
Bit 2
–
Vendor test mode
0
Reserved. Write with ‘0’
Bit 1
–
Vendor test mode
1
Test mode. Write with ‘1’
Bit 0
–
Vendor test mode
1
Test mode. Write with ‘1’
Byte 16: Reserved Register
Bit
Pin#
Name
Default
Description
Bit 7
–
Reserved
0
Reserved
Bit 6
–
Reserved
0
Reserved
Bit 5
–
Reserved
0
Reserved
Bit 4
–
Reserved
0
Reserved
Bit 3
–
Reserved
0
Reserved
Bit 2
–
Reserved
0
Reserved
Bit 1
–
Reserved
0
Reserved
Byte 17: Reserved Register
Bit
Pin#
Name
Default
Description
Bit 7
–
Reserved
0
Reserved
Bit 6
–
Reserved
0
Reserved
Bit 5
–
Reserved
0
Reserved
Bit 4
–
Reserved
0
Reserved
Bit 3
–
Reserved
0
Reserved
Bit 2
–
Reserved
0
Reserved
Bit 1
–
Reserved
0
Reserved