Overview of MSP430 Timers
TIMER_A/B Nomenclature
The nomenclature of the TIMER_A and _B peripherals is a little unusual. First of all, you may
have already noticed that the MSP430 team often adds one of two suffixes to their peripheral
names to indicate when features have been added (or modified).
• Some peripherals, such as the Watchdog Timer go from “WDT” to “WDT+”. That is, they add
a “+” to indicate the peripheral has been updated (usually with additional features).
• Other peripherals are enumerated with letters. For example, three sophisticated MSP430
timers have been introduced: TIMER_A, TIMER_B, and TIMER_D.
(What happened to _C?
Even I don’t know that. <ed>)
The use of a suffix is the generic naming convention found on the MSP430. With the timers,
though, there are a couple more naming variations to be discussed.
As we will cover in great detail during this chapter, these timers contain one or more Capture and
Compare Registers (CCR); these are useful for creating sophisticated timings, interrupts and
waveforms. The more CCR registers a timer contains, the more independent waveforms that can
be generated. To this end, the documentation often includes the number of CCR registers when
listing the name of the timer. For example, if TIMER_A on a given device has 5 CCR registers,
they often name it:
Timer_A5
But wait, that’s not all. What happens when a device, such as the ‘F5529 has more than one
instance of TIMER_A? Each of these instances needs to be enumerated as well. This is done by
appending the instance number after the word “Timer”, as in Timer0.
To summarize, here’s the long (and short) names for each of the ‘F5529 TIMER_A modules:
Instance Long Name Short Name
0 Timer0_A5 TA0
1 Timer1_A3 TA1
2 Timer2_A3 TA2
6 - 4 MSP430 Workshop - Timers
To Next Page
Loading...
Need help?
General
