CY28404 Cypress Semiconductor, CY28404 Datasheet - Page 14

• Manufacturer Part Number: CY28404
• Description: CK409-COMPLIANT CLOCK SYNTHESIZER
• Manufacturer: Cypress Semiconductor

CY28404
W ATCHDOG TIMER
PROGRAMMING
RESET W ATCHDOG TIMER
Set WD Timer Bits = 0
Clear WD Alarm bit = 0
INITIALIZE W ATCHDOG TIMER
Set Frequency Revert Bit
Set WD Timer Bits
CHANGE FREQ BY
CHANGE FREQ BY SET DIAL-A-
SET SOFTW ARE FSEL
FREQUENCY
Set SW Freq_Sel bits
Load M and N Registers
Set FS override bit
Set Pro_Freq_EN = 1
WD timer Reload bit
Set WD Timer Bits to
setting from 0 to 1
Extend Time
YES
NO
System need Extend
W D Alarm bit = 1
Time for next count
YES
NO
Frequency Revert Bit = 0
Frequency Revert Bit = 1
CLEAR W D TIMER
Set WD timer Bits = 0
Set Frequency to
Set Frequency to
FS_HW_Latched
FS_SW Setting
Exit W D Timer
SRESET# = 0 for 3 msec
Reset & Revert
Frequency back
Figure 7. Watchdog Self-Recovery Sequence Flowchart
Document #: 38-07510 Rev. *B
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