Posted on May 17, 2011 at 12:07Hello,
I am having a problem where by using the sample timer 0 files my I2C gets slowed down.
I am using timer 2 for sound generation, timer 1 for Uarts 0 and 1 and timer 0 for pausing for 1ms, 10ms, and 1 sec delays. If I increase the countdown spead of timer 0 my I2C will speed up hugely. If I have it set to the default for ''upsd3200_timer.c'' then my I2C goes unbelievably slow.
I have tried running at different frequencies for the I2C, it doesn't seem to matter. Why would a timer effect the I2C speed? Is it based off of a timer?
I have tried to download the PDF file Application Note regaurding I2C for the DK3234 off of ST's website but the link does not work. Could someone send me the PDF maybe?
Here is my init routine for the I2C:
P3SFS |= 0xC0; // Enable P3.7 for SCL, P3.6 for SDA
S2CON |= 0x03; // Setup I2C-2 for 300KHz (36MHz XTAL)
i2c_init_flag = 1; // set init done flag
i2c_timeout_flag = 0; // clear timeout error flag
PX1 = 0; // set low priority for INT1
IPA |= 0x02; // set high priority for EI2C
IEA |= 0x02; // set EI2C I2C Int. Enable bit
here is my init routine for timer 0:
EA = 0; /* disable interrupts */
timer0_tick = 0;
TR0 = 0; /* stop timer 0 */
TMOD &= 0xF0; /* clear timer 0 mode bits - bottom 4 bits */
TMOD |= 0x01; /* put timer 0 into 16-bit no prescale */
// Calculate timer rollover to be 10ms periods (100hz)
timer0_value = 0x10000 - ( ((FREQ_OSC * 5L) / 6L) - 17L);
TL0 = (timer0_value & 0x00FF);
TH0 = (timer0_value >> 8);
PT0 = 1; /* set high priority interrupt for timer 0 */
ET0 = 1; /* enable timer 0 interrupt */
TR0 = 1; /* start timer 0 */
EA = 1; /* enable interrupts */
Thanks in advance!!
