CY28316
Document #: 38-07125 Rev. *B
Page 9 of 18
Byte 13: Programmable Frequency Select N-Value Register
Bit
Name
Default
Pin Description
Bit 7
CPU_FSEL_N7
0
If Prog_Freq_EN is set, CY28316 will use the values programmed in
CPU_FSEL_N[7:0] and CPU_FSEL_M[6:0] to determine the CPU output
frequency. 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, CY28316 will use the same
frequency ratio stated in the Latched FS[4:0] register. When it is set, CY28316
will use the frequency ratio stated in the SEL[4:0] register. CY28316 supports
programmable CPU frequencies ranging from 50 MHz to 248 MHz.
Bit 6
CPU_FSEL_N6
0
Bit 5
CPU_FSEL_N5
0
Bit 4
CPU_FSEL_N4
0
Bit 3
CPU_FSEL_N3
0
Bit 2
CPU_FSEL_N2
0
Bit 1
CPU_FSEL_N1
0
Bit 0
CPU_FSEL_N0
0
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, CY28316 will use the values programmed in
CPU_FSEL_N[7:0] and CPU_FSEL_M[6:0] to determine the CPU output
frequency. 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, CY28316 will use the same
frequency ratio stated in the Latched FS[4:0] register. When it is set, CY28316
will use the frequency ratio stated in the SEL[4:0] register. CY28316 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.