HD404369F datasheet(68/117 Pages) RENESAS

68 / 117 page

HD404369 Series

(N + 1)

256

(256 – N)

TMC3 = 0

(free-running

timer)

TMC3 = 1

(reload timer)

Notes: T: Input clock period supplied to counter. (The clock source and system clock division ratio are

determined by timer mode register C.)

N: Value of timer write register C. (When N = 255 ($FF), PWM output is fixed low.)

Figure 49 PWM Output Waveform

Registers for Timer C Operation: By using the following registers, timer C operation modes are selected

and the timer C count is read and written.

 Timer mode register C (TMC: $00D)

 Port mode register A (PMRA: $004)

 Timer write register C (TWCL: $00E, TWCU: $00F)

 Timer read register C (TRCL: $00E, TRCU: $00F)

• Timer mode register C (TMC: $00D): Four-bit write-only register that selects the free-running/reload

timer function, input clock source, and the prescaler division ratio as shown in figure 50. It is reset to $0

by MCU reset.

Writing to this register is valid from the second instruction execution cycle after the execution of the

previous timer mode register C write instruction. Setting timer C’s initialization by writing to timer

write register C (TWCL: $00E, TWCU: $00F) must be done after a mode change becomes valid.

HD404369F Scheda tecnica(PDF) 68 Page - Renesas Technology Corp