Chapter 4 Timer Functions

The period of the output signal from the port is 1/2 of the period set in the TM4OCH, TM4OCL register.

Timer Pulse Output Function

Settings for the timer pulse output function are listed below.

(1)Set the TM4EN flag of the timer 4 mode register (TM4MD) to "0" so that the count operation of timer 4 is stopped.

(2)Set bit 4 of the port 1 output/input mode register (P1OMD) to the special function pin setting. Bit 4 of port 1 will be specified as the pulse output pin.

(3)Use the TM4CK2 to 0 flags of the TM4MD register to select fosc, fs/4, or fs/16 as the clock source.

(4)Set the TM4PWM flag of the TM4MD register to "0" so that 16-bit timer operation is selected.

(5)Set a value in compare register 4 (TM4OCH, TM4OCL).

(6)Set the TM4EN flag of the TM4MD register to "1" to start the timer.

(7)When timer 4 begins operation, binary counter 4 will count upward from X'0000'.

(8)When the value of binary counter 4 matches that of the TM4OCH and TM4OCL registers, the timer 4 interrupt request flag is set, and the binary counter 4 is reset to X'0000' and begins to count upward again.

Matches TM4OCH, TM4OCL register

Binary counter 4

TM4OUT

Figure 4-3-3 Timer Pulse Output Timing

72 16-bit Timer Operation (timer 4)

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Panasonic MN101C00 user manual Timer Pulse Output Timing, Matches TM4OCH, TM4OCL register Binary counter