1
2
0
1
2
0
Prescale counter
(TDDR34)
Timer counter
15
16
0
(TIM34)
32-bit timer settings: count = TIM34 = 15; period = PRD34 = 16
4-bit prescaler settings: count = TDDR34 = 1; period = PSC34 = 2
Timer counter
incremented
Prescale counter
reset
Prescale counter
reset
Timer counter
reset
Introduction
1477
SPRUH82C – April 2013 – Revised September 2016
Copyright © 2013–2016, Texas Instruments Incorporated
64-Bit Timer Plus
30.1.5.4.2.2.1 32-Bit Timer With a 4-Bit Prescaler
In the unchained mode, the 4-bit prescale is clocked by the internal clock. The 4-bit prescaler uses the
timer divide-down ratio (TDDR34) bit in TGCR to form a 4-bit prescale counter register and the prescale
counter bits (PSC34) to form a 4-bit prescale period register (see
). When the timer is enabled,
the prescale counter starts incrementing by 1 at every timer input clock cycle. One cycle after the prescale
counter matches the prescale period, a clock signal is generated for the 32-bit timer.
The 32-bit timer uses TIM34 as a 32-bit timer counter register and PRD34 as a 32-bit timer period
register. The 32-bit timer is clocked by the output clock from the 4-bit prescaler (see the example in
). The timer counter increments by 1 at every prescaler output clock cycle. When the timer
counter matches the period, a maskable timer interrupt (TINT34) and a timer DMA event (TEVT34) are
generated. When the timer is configured in continuous mode, the timer counter is reset to 0 on the cycle
after the timer counter reaches the timer period. The timer can be stopped, restarted, reset, or disabled
using the TIM34RS bit in TGCR. For timer 3:4, the lower 16 bits of the timer control register (TCR) have
no control.
Figure 30-7. Dual 32-Bit Timers Unchained Mode Example
30.1.5.4.2.2.2 32-Bit Timer with No Prescaler
The other 32-bit timer (timer 1:2) uses TIM12 as the 32-bit counter register and PRD12 as a 32-bit timer
period register (see
). When the timer is enabled, the timer counter increments by 1 at every
timer input clock cycle. When the timer counter matches the timer period, a maskable timer interrupt
(TINT12), a timer DMA event (TEVT12), and a timer output event on TM64P_OUT12 are generated.
When the timer is configured in continuous mode, the timer counter is reset to 0 on the cycle after the
timer counter reaches the timer period. The timer can be stopped, restarted, reset, or disabled using the
TIM12RS bit in TGCR. For timer 1:2, the upper 16 bit of the timer control register (TCR) have no control.