diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/arch/msp430fr5969lp/driver/stdout.cc | 30 |
1 files changed, 29 insertions, 1 deletions
diff --git a/src/arch/msp430fr5969lp/driver/stdout.cc b/src/arch/msp430fr5969lp/driver/stdout.cc index 321785b..b3e8b4d 100644 --- a/src/arch/msp430fr5969lp/driver/stdout.cc +++ b/src/arch/msp430fr5969lp/driver/stdout.cc @@ -1,12 +1,40 @@ #include "driver/stdout.h" #include <msp430.h> +/* + * Baud rate calculation according to datasheet: + * N := f_{BRCLK} / Baudrate = F_CPU / 115200 in our case + * if N <= 16: OS16 = 0, UCBR0 = int(N) + * if N > 16: OS16 = 1, UCBR0 = int(N/16), UCBRF0 = int(((n/16) - int(n/16)) * 16) = int(N)%16 + * Set UCBRS0 according to table 21-4 + */ + void StandardOutput::setup() { UCA0CTLW0 |= UCSWRST; +#if F_CPU == 16000000UL + // 16M / 115200 == 138.88889 -> UCOS16 = 1, UCBR0 = 16, UCBRF0 = 10, UCBRS0 = 0xf7 ("0.8751") + UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK; + UCA0MCTLW = UCOS16 | (10<<4) | 0xF700; + UCA0BR0 = 8; +#elif F_CPU == 8000000UL + // 8M / 115200 == 69.444444 -> UCOS16 = 1, UCBR0 = 4, UCBRF0 = 5, UCBRS0 = 0x55 ("0.4378") + UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK; + UCA0MCTLW = UCOS16 | (5<<4) | 0x5500; + UCA0BR0 = 4; +#elif F_CPU == 4000000UL + // 4M / 115200 == 34.722222 -> UCOS16 = 1, UCBR0 = 2, UCBRF0 = 2, UCBRS0 = 0xbb ("0.7147") + UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK; + UCA0MCTLW = UCOS16 | (2<<4) | 0xbb00; + UCA0BR0 = 2; +#elif F_CPU == 1000000UL + // 1M / 115200 == 8.6805556 -> UCOS16 = 0, UCBR0 = 8, UCBRF0 = 0, UCBRS0 = 0xd6 ("0.6667") UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK; - UCA0MCTLW = UCOS16 | (10<<5) | 0xF700; + UCA0MCTLW = 0x5500; UCA0BR0 = 8; +#else +#error Unsupported F_CPU +#endif UCA0IRCTL = 0; UCA0ABCTL = 0; |