M16C Micro timer pwm port

Hey Guys,

im trying 2 generate a pwm signal to drive a stepper motor, got hold of
Mitsubishi's example code which goes like this...

#include "sfr62.h"

void main(void);
void initPorts(void);

void initPorts(void)
{
pd0 = 0xFF; // output mode
pd1 = 0xFF; // output mode
pu00 = 0; // no pull up for P0_0 to P0_3
pu01 = 0; // no pull up for P0_4 to P0_7
pu02 = 0; // no pull up for P1_0 to P1_3
p1 = 0xFF; // disable LED1 and LED2
p0 = 0xFF; // turn off all segments

pd7 = 0XFF; // set port P7 to output mode
pu16 = 0; // no pull up for P7_0 to P7_3 , P7_0 & P7_1 needs a pull-up
pu17 = 0; // no pull up for P7_4 to P7_7
p7 = 0XFF; // initial port P7 data
}

void main(void)
{
initPorts();
ta1mr = 0X27; //set timerA1 to 8bit PWM mode
ta1 = 0X0102; //set pwm cycle to 50us
tabsr = 0x02; //start the timerA1
}

Now using this code i get a signal on my pin p7.2 which is nearly 50us
but i dont understand the initports function.....it changes port 0,1
and 7 to o/p mode thats ok but what is up with the "pull up" part makes
no sense. For the sake of understanding i changed all the settings to
port2 from port7 but that has made no difference i still get a signal
at p7.2

ny help appreciated
thanks
Nav

.

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