Error in HserSend: usart.h (0.9 12/8/2009)

[Santiago]

Now is:

sub HSerSend(In SerData)

    #ifdef PIC

        #ifdef USART_BLOCKING

            Wait While TXIF = On '...................HERE
        #endif

        TXREG = SerData

    #endif

it should be:

sub HSerSend(In SerData)

    #ifdef PIC

        #ifdef USART_BLOCKING

            Wait While TXIF = Off

        #endif

        TXREG = SerData

    #endif

And... Just an optimisation in InitUsart. This save two unneeded banksels:

Sub InitUSART

    #ifdef PIC

        'Set baud rate

        SPBRG = SPBRGL_TEMP

        #ifdef Bit(BRG16)

            SPBRGH = SPBRGH_TEMP

            BRG16 = BRG16_TEMP

        #endif

        BRGH = BRGH_TEMP

       

        'Enable async mode

        Set SYNC Off

        'Enable TX and RX
        Set TXEN On

        Set CREN On

        'Enable Serial Port

        Set SPEN On

    #endif

Just first set all bits in bank1 registers , then the bank0 ones.

[Santiago]

There is also a problem at high baudrates, because the SPBRG calculation takes just the integer part of the result, and it should be rounded to +1 when the decimal > 0.5.

For example at 115200 teoretical SPBRG should be 9.85, but 9 is parsed, then it does not work, but with SPBRG=10 it works ok. For lower speeds the error is small enought to not create problems.

This works for me (usart.h):

SPBRG_TEMP = ChipMHz / USART_BAUD_RATE / 16 * 1000000
if int(SPBRG_TEMP + 0.5) = int(SPBRG_TEMP) then SPBRG_TEMP -= 1