SPRZ200E
TMS320VC5509A Silicon Errata
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Usage Notes
Usage Notes highlight and describe particular situations where the device’s behavior may not match the presumed
or documented behavior. This may include behaviors that affect device performance or functional correctness.
These notes will be incorporated into future documentation updates for the device (such as the device-specific
data sheet), and the behaviors they describe will not be altered in future silicon revisions.
RTC: Seconds Alarm Functionality
On the 5509A device, the Seconds Alarm Register (RTCSECA) cannot be used to generate an alarm every
second, but the update-ended interrupt can.
The Real-Time Clock (RTC) executes an update cycle once per second to update the current time in the
time/calendar registers:
•
Seconds Register (RTCSEC)
•
Minutes Register (RTCMIN)
•
Hours Register (RTCHOUR)
•
Day of the Week and Day Alarm Register (RTCDAYW)
•
Day of the Month (Date) Register (RTCDAYM)
•
Month Register (RTCMONTH)
•
Year Register (RTCYEAR)
At the end of every update cycle, the RTC sets the update-ended interrupt flag (UF) in the Interrupt Flag Register
(RTCINTFL). If the update-ended interrupt enable bit (UIE) in the Interrupt Enable Register (RTCINTEN) is set to 1,
an interrupt request is sent to the CPU.
