
CY28316
Document #: 38-07125 Rev. *B
Page 7 of 18
Byte 7: Control Register 7
Bit
Pin#
Name
Default
Pin Description
Bit 7
–
Reserved
0
Reserved.
Bit 6
25
24_48MHz_DRV
1
0 = Norm, 1 = High Drive.
Bit 5
26
48MHz_DRV
1
0 = Norm, 1 = High Drive.
Bit 4
–
Reserved
0
Reserved.
Bit 3
–
Reserved
0
Reserved.
Bit 2
–
Reserved
0
Reserved.
Bit 1
–
Reserved
0
Reserved.
Bit 0
–
Reserved
0
Reserved.
Byte 8: Vendor ID and Revision ID Register (Read Only)
Bit
Name
Default
Pin Description
Bit 7
Revision_ID3
0
Revision ID bit[3].
Bit 6
Revision_ID2
0
Revision ID bit[2].
Bit 5
Revision_ID1
0
Revision ID bit[1].
Bit 4
Revision_ID0
0
Revision ID bit[0].
Bit 3
Vendor_ID3
1
Bit[3] of Cypress’s Vendor ID. This bit is read-only.
Bit 2
Vendor_ID2
0
Bit[2] of Cypress’s Vendor ID. This bit is read-only.
Bit 1
Vendor _ID1
0
Bit[1] of Cypress’s Vendor ID. This bit is read-only.
Bit 0
Vendor _ID0
0
Bit[0] of Cypress’s Vendor ID. This bit is read-only.
Byte 9: System RESET and Watchdog Timer Register
Bit
Name
Default
Pin Description
Bit 7
SDRAM_DRV
0
SDRAM clock output drive strength.
0 = Normal.
1 = High Drive.
Bit 6
PCI_DRV
0
PCI clock output drive strength.
0 = Normal.
1 = High Drive.
Bit 5
Reserved
0
Reserved
Bit 4
RST_EN_WD
0
This bit will enable the generation of a Reset pulse when a Watchdog Timer
time-out occurs.
0 = Disabled.
1 = Enabled.
Bit 3
RST_EN_FC
0
This bit will enable the generation of a Reset pulse after a frequency change
occurs.
0 = Disabled.
1 = Enabled.
Bit 2
WD_TO_STATUS
0
Watchdog Timer Time-out Status bit.
0 = No time-out occurs (Read); Ignore (Write).
1 = Time-out occurred (Read); Clear WD_TO_STATUS (Write).
Bit 1
WD_EN
0
0 = Stop and reload Watchdog Timer. Unlock CY28316 from recovery frequency
mode.
1 = Enable Watchdog Timer. It will start counting down after a frequency change
occurs.
Note: CY28316 will generate a system Reset, reload a recovery frequency, and
lock itself into a recovery frequency mode after a Watchdog Timer time-out
occurs. Under recovery frequency mode, CY28316 will not respond to any
attempt to change output frequency via the SMBus control bytes. System
software can unlock CY28316 from its recovery frequency mode by clearing the
WD_EN bit.