Maxim-integrated MAXQ Family Users Guide: MAXQ2010 Supplement Uživatelský manuál stáhnout pdf (Strana 123)

MAXQ Family User’s Guide:

MAXQ2010 Supplement

21-12

21.2.8 EXENB Control During PWM/Output Control Mode

The TBB input function (EXENB = 1) and the PWM/output control function (TBCS:TBCR<>00b) can be enabled at the

same time. However, the input function changes slightly when this is done. In this configuration, the detection of a fall-

ing edge on the TBB pin results in setting of the EXFB interrupt flag, but does not force an autoreload.

21.3 Timer B Examples

21.3.1 Timer B Example: Reloading Timer Mode

move PD5.2, #1 ; Set P5.2 to output mode

move PO5.2, #1 ; Drive high (LED off)

move TB0CN, #0000010000000000b ; Timer mode, reload mode, clock/256

move TB0R, #8000h ; Reload every 8000h timer cycles

move TB0CN.2, #1 ; Start timer

;; Reload time is 1/sysclk * 256 * 8000h == 838ms

timerLoop:

move C, TB0CN.7 ; Check reload flag

jump NC, timerLoop

move TB0CN.7, #0 ; Clear reload flag

move Acc, PO5

xor #0100b ; Toggle bit 2

move PO5, Acc

jump timerLoop

1 2 ... 118 119 120 121 122 123 124 125 126 127 128 ... 146 147

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Maxim-integrated MAXQ Family Users Guide: MAXQ2010 Supplement Uživatelský manuál Strana 123