Reply by jannethgil ●September 27, 20052005-09-27
Thank You Very Much :) --- In AT91SAM7@AT91..., "jannethgil" <jannethgil@y...> wrote:
> Hi
>
> Does anybody has an simple example on using usart interrupts using
> the
> GCC compiler for an AT91 ARM7 microcontroller?.
>
> I just need to get started.
>
> Any links, sugestions or source code will be appreciated
>
> Thanks :)

Reply by Mike Wolfram ●July 15, 20052005-07-15
Just a snippet from a current project:

#define BUFFER_SIZE 256

#ifdef MD_USE_USART0
mdByte
com0_recBuffer[BUFFER_SIZE],
com0_sendBuffer[BUFFER_SIZE];
mdBuffer
com0_ReceiveBuffer,
com0_SendBuffer;
const AT91PS_USART
com0 = AT91C_BASE_US0;
mdBool
ser_bTransmission = false; void usart0_irq_handler()
{
mdUInt32
status;

status = com0->US_CSR;
status &= com0->US_IMR;

if (status & AT91C_US_TXRDY)
{
if (com0_SendBuffer.pos == com0_SendBuffer.len)
{
com0->US_IDR = AT91C_US_TXRDY;

ser_bTransmission = false;
}
else
{
com0->US_THR = com0_SendBuffer.buf[com0_SendBuffer.pos++];

if (com0_SendBuffer.pos >= com0_SendBuffer.size)
com0_SendBuffer.pos = 0;
}
}

if (status & AT91C_US_RXRDY)
{
if (com0_ReceiveBuffer.len >= com0_ReceiveBuffer.size)
com0_ReceiveBuffer.len = 0;

com0_ReceiveBuffer.buf[com0_ReceiveBuffer.len++] = com0->US_RHR;
}

com0->US_CR = AT91C_US_RSTSTA;
AT91C_BASE_AIC->AIC_EOICR = 0;
} void usart0_init()
{
AT91F_US0_CfgPMC();
AT91F_PIO_CfgPeriph(AT91C_BASE_PIOA,
((mdUInt32) AT91C_PA5_RXD0) |
((mdUInt32) AT91C_PA6_TXD0),
0
);

AT91F_US_Configure(com0, TARGET_MCK, AT91C_US_ASYNC_MODE, USART0_BAUDRATE,
0);

com0->US_CR = AT91C_US_RXEN | AT91C_US_TXEN;

com0->US_IER = AT91C_US_RXRDY;

__md_ulDummy = com0->US_RHR;

AT91F_AIC_ConfigureIt(AT91C_BASE_AIC,
AT91C_ID_US0,
USART0_INTERRUPT_LEVEL,
AT91C_AIC_SRCTYPE_INT_LEVEL_SENSITIVE,
usart0_irq_handler
);
AT91F_AIC_EnableIt(AT91C_BASE_AIC, AT91C_ID_US0);

com0_ReceiveBuffer.size = BUFFER_SIZE;
com0_ReceiveBuffer.pos = 0;
com0_ReceiveBuffer.len = 0;
com0_ReceiveBuffer.buf = com0_recBuffer;

com0_SendBuffer.size = BUFFER_SIZE;
com0_SendBuffer.pos = 0;
com0_SendBuffer.len = 0;
com0_SendBuffer.buf = com0_sendBuffer;
} void usart0_send(const mdByte *buf, mdUInt32 len)
{
mdUInt32
i;

if (len > BUFFER_SIZE)
len = BUFFER_SIZE;

for (i = 0; i < len; i++)
{
if (com0_SendBuffer.len >= com0_SendBuffer.size)
com0_SendBuffer.len = 0;
com0_SendBuffer.buf[com0_SendBuffer.len++] = buf[i];
}

ser_bTransmission = true;

com0->US_IER = AT91C_US_TXRDY | AT91C_US_RXRDY;
} mdUInt32 usart0_received()
{
mdUInt32
len;

if (com0_ReceiveBuffer.pos <= com0_ReceiveBuffer.len)
len = com0_ReceiveBuffer.len - com0_ReceiveBuffer.pos;
else
len = com0_ReceiveBuffer.size - com0_ReceiveBuffer.pos +
com0_ReceiveBuffer.len;

return len;
} void usart0_get(mdByte *dest, mdUInt32 len)
{
while (len--)
{
if (com0_ReceiveBuffer.pos >= com0_ReceiveBuffer.size)
com0_ReceiveBuffer.pos = 0;

*dest++ = com0_ReceiveBuffer.buf[com0_ReceiveBuffer.pos++];
}
} void usart0_clear()
{
com0_ReceiveBuffer.len = 0;
com0_ReceiveBuffer.pos = 0;
com0_SendBuffer.len = 0;
com0_SendBuffer.pos = 0;
} --
Mike On Tuesday 12 July 2005 01:08, jannethgil wrote:
> Hi
>
> Does anybody has an simple example on using usart interrupts using
> the
> GCC compiler for an AT91 ARM7 microcontroller?.
>
> I just need to get started.
>
> Any links, sugestions or source code will be appreciated
>
> Thanks :) >
>
> YAHOO! GROUPS LINKS >



Reply by jannethgil ●July 11, 20052005-07-11
Hi

Does anybody has an simple example on using usart interrupts using
the
GCC compiler for an AT91 ARM7 microcontroller?.

I just need to get started.

Any links, sugestions or source code will be appreciated

Thanks :)