In Sitara I'm able to see some data on the oscilloscope , when I write sumthing onto the UART transmit fifo in CIR mode , but the waveform which I'm getting is something which i don't expect , I think I have configured the register CFPS for 36 KhZ , newayz even if we don't configure it will be 38 Khz , Now in the transmit fifo when I'm writing 0x55 , what my understanding says is that I should get 4 pulses but I'm getting something different , anyone has ne ideas , what probablly is happening
what I'm doing in ISR
ISR()
{
serial_out(uart_port, UART_TX, 0x00)
serial_out(uart_port, UART_TX, 0x00)
serial_out(uart_port, UART_TX, 0x00)
serial_out(uart_port, UART_TX, 0x00)
serial_out(uart_port, UART_TX, 0x55)
}
this things are written onto the transmit fifo register , from where it is pushed out as soon as this is empty , empty fifo interrupt is generated and in iSR i do the above so I expecting 4 pulse , but I'm getting some unexpected waveform .like this
http://www.pixentral.com/show.php?picture=16nceqhWAfMMT2cO72fdCXELPXVfD0
is ot because of frequency settings which i have done in CFPS register , or its because of DLL and DLH register to which i have just wriiten some random value .