ZHCU032K December 2004 – August 2022 MSP430AFE221 , MSP430AFE222 , MSP430AFE223 , MSP430AFE231 , MSP430AFE232 , MSP430AFE233 , MSP430AFE251 , MSP430AFE252 , MSP430AFE253 , MSP430F2001 , MSP430F2002 , MSP430F2003 , MSP430F2011 , MSP430F2012 , MSP430F2013 , MSP430F2101 , MSP430F2111 , MSP430F2112 , MSP430F2121 , MSP430F2122 , MSP430F2131 , MSP430F2132 , MSP430F2132-EP , MSP430F2232 , MSP430F2234 , MSP430F2252 , MSP430F2252-Q1 , MSP430F2254 , MSP430F2272 , MSP430F2272-Q1 , MSP430F2274 , MSP430F2274-EP , MSP430F233 , MSP430F2330 , MSP430F235 , MSP430F2350 , MSP430F2370 , MSP430F2410 , MSP430F2416 , MSP430F2417 , MSP430F2418 , MSP430F2419 , MSP430F247 , MSP430F2471 , MSP430F248 , MSP430F2481 , MSP430F249 , MSP430F2491 , MSP430F2616 , MSP430F2617 , MSP430F2618 , MSP430F2619 , MSP430G2001 , MSP430G2101 , MSP430G2102 , MSP430G2111 , MSP430G2112 , MSP430G2121 , MSP430G2131 , MSP430G2132 , MSP430G2152 , MSP430G2153 , MSP430G2201 , MSP430G2201-Q1 , MSP430G2202 , MSP430G2203 , MSP430G2210 , MSP430G2211 , MSP430G2212 , MSP430G2213 , MSP430G2221 , MSP430G2230 , MSP430G2231 , MSP430G2231-Q1 , MSP430G2232 , MSP430G2233 , MSP430G2252 , MSP430G2253 , MSP430G2302 , MSP430G2303 , MSP430G2312 , MSP430G2313 , MSP430G2332 , MSP430G2333 , MSP430G2352 , MSP430G2353 , MSP430G2402 , MSP430G2403 , MSP430G2412 , MSP430G2413 , MSP430G2432 , MSP430G2433 , MSP430G2444 , MSP430G2452 , MSP430G2453 , MSP430G2513 , MSP430G2533 , MSP430G2544 , MSP430G2553 , MSP430G2744 , MSP430G2755 , MSP430G2855 , MSP430G2955 , MSP430TCH5E
如果定时器周期肯定不会与 TBR(最大)计数相同, 且需要产生对称的脉冲时,才会使用增/减模式。定时器重复递增计数比较锁存器 TBCL0 的值,之后再减至 0,如在图 13-7中所示。该周期是 TBCL0 值的 2 倍。
TBCL0 > TBR(最大)
如果 TBCL0 > TBR(最大),那么计数操作就和连续模式的配置一样。不会从 TBR(最大)减到 0。
计数方向是锁定的。这就使得定时器停止后再能在停止前以相同的方向重新启动计数。如果不想这样的话,就需要用 TBCLR 位来清零方向。TBCLR 位也会清零 TBR 值和时钟分频。
在增减模式中,TBCCR0 CCIFG 中断标志和 TBIFG 中断标志在该周期中只被置位一次,它们相隔 1/2 个定时器周期。当计时器从 TBCL0-1 计数到 TBCL0 时,会设置 TBCCR0 CCIFG 中断标志,当计时器从 0001h 向下计数到 0000h 时,会设置 TBIFG。图 13-8说明了标志置 1 周期。