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/*
* COPYRIGHT (c) 2010.
* Cobham Gaisler AB.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#include <grlib/apbuart.h>
#include <rtems/score/cpuimpl.h>
void apbuart_outbyte_wait(const struct apbuart_regs *regs)
{
while ( (regs->status & APBUART_STATUS_TE) == 0 ) {
/* Lower bus utilization while waiting for UART */
_CPU_Instruction_no_operation();
_CPU_Instruction_no_operation();
_CPU_Instruction_no_operation();
_CPU_Instruction_no_operation();
_CPU_Instruction_no_operation();
_CPU_Instruction_no_operation();
_CPU_Instruction_no_operation();
_CPU_Instruction_no_operation();
}
}
void apbuart_outbyte_polled(struct apbuart_regs *regs, char ch)
{
apbuart_outbyte_wait(regs);
regs->data = (uint8_t) ch;
}
int apbuart_inbyte_nonblocking(struct apbuart_regs *regs)
{
/* Clear errors */
regs->status = ~APBUART_STATUS_ERR;
if ((regs->status & APBUART_STATUS_DR) == 0) {
return -1;
}
return (uint8_t) regs->data;
}
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