/*
* Start sending (unless already sending)
*/
void uart_send_next_msg(void)
{
// Disable interrupts to make sure UartTxBuffer state isn't modified in the middle
__bic_status_register(GIE);
if (UartTxBufferLength > 0 && uart_state != UART_STATE_TX) {
uart_state = UART_STATE_TX;
UCA0TXBUF = UartTxBuffer[UartTxBuffer_i]; // Send first byte
}
// Enable interrupts
__bis_status_register(GIE);
}
/* Change the current power-saving mode. */
enum lpm_mode lpm_set(enum lpm_mode target)
{
enum lpm_mode last_mode = lpm_get();
switch (target)
{
case LPM_ON:
// fully running MCU
__bic_status_register(CPUOFF | OSCOFF | SCG0 | SCG1);
break;
case LPM_IDLE:
// lightest mode => LPM0 mode of MSP430
__bic_status_register(OSCOFF | SCG0 | SCG1);
// only stops CPU block
__bis_status_register(CPUOFF);
break;
case LPM_SLEEP:
// mid-level mode => LPM1 mode of MSP430
__bic_status_register(OSCOFF | SCG1);
// stops CPU and master clock blocks
__bis_status_register(CPUOFF | SCG0);
break;
case LPM_POWERDOWN:
// deep-level mode => LPM3 mode of MSP430
__bic_status_register(OSCOFF);
// stops all blocks except auxiliary clock (timers)
__bis_status_register(CPUOFF | SCG0 | SCG1);
break;
case LPM_OFF:
// MCU totally down (LPM4), only RESET or NMI can resume execution
__bis_status_register(CPUOFF | OSCOFF | SCG0 | SCG1); // all blocks off
break;
default:
printf("ERROR: trying to set an invalid low-power mode!\n");
printf(" Operation aborted.\n\n");
}
return last_mode;
}
/*
* Append new message to transmit buffer
*/
uint8_t uart_tx_append_msg(unsigned char *buf, unsigned char len)
{
int i;
// Disable interrupts to make sure UartTxBuffer state isn't modified in the middle
__bic_status_register(GIE);
// Check that there's enough space
if (UartTxBufferLength + len >= UART_BUF_LEN) {
// Enable interrupts
__bis_status_register(GIE);
return 0;
}
for (i = 0; i < len; ++i) {
UartTxBuffer[UartTxBufferLength + i] = buf[i];
}
UartTxBufferLength += i;
// Enable interrupts
__bis_status_register(GIE);
return i;
}
/* resume the MSP430 MCU */
inline void lpm_awake(void)
{
// disable all power savings mechanisms
__bic_status_register(CPUOFF | OSCOFF | SCG0 | SCG1);
}
