Mitsubishi Electric M32R Series User Manual page 488

Mitsubishi 32-bit risc single-chip microcomputers

Table of Contents

(2) Reload register updates in TOM PWM output mode

In PWM output mode, when the timer remains idle, reload 0 and reload 1 registers are updated at

the same time data are written to the registers. But when the timer is active, reload 1 register is

updated by updating reload 0 register. However, when you read reload 0 and reload 1 registers,

the values you get are always the data written to the registers.

Internal bus

Prescaler output

Figure 10.9.6 PWM Circuit Diagram

If you want to rewrite reload 0 and reload 1 registers while the timer is operating, rewrite reload 1

updated synchronously with PWM periods, from which the timer starts operating again. This

operation can normally be performed collectively by accessing register addresses wordwise (in

32 bits) beginning with that of reload 1 register. (Data are automatically written to reload 1 and

then reload 0 registers in succession.)

If you update the reload registers in reverse by updating reload 0 register first and then reload 1

values you get are always the data written to the registers, and not the reload values being

actually used.

Note that when updating the PWM period, if the PWM period is terminated before you finished

writing to reload 0, the PWM period is not updated in the current period and what you've set is

reflected in the next period.

16-bit counter

MULTIJUNCTION TIMERS

10.9 TOM (Output-related 16-bit Timer)

PWM mode control