Texas Instruments MSP430x1xx Instrukcja Użytkownika Strona 280

  • Pobierz
  • Dodaj do moich podręczników
  • Drukuj
  • Strona
    / 432
  • Spis treści
  • BOOKMARKI
  • Oceniono. / 5. Na podstawie oceny klientów
Przeglądanie stron 279
USART Operation: UART Mode
13-20
USART Peripheral Interface, UART Mode
Receive-Start Edge Detect Conditions
When URXSE = 1, glitch suppression prevents the USART from being
accidentally started. Any low-level on URXDx shorter than the deglitch time t
τ
(approximately 300 ns) will be ignored by the USART and no interrupt request
will be generated as shown in Figure 13−12. See the device-specific
datasheet for parameters.
Figure 13−12. Glitch Suppression, USART Receive Not Started
URXDx
URXS
t
τ
When a glitch is longer than t
τ,
or a valid start bit occurs on URXDx, the USART
receive operation is started and a majority vote is taken as shown in
Figure 13−13. If the majority vote fails to detect a start bit the USART halts
character reception.
If character reception is halted, an active BRCLK is not necessary. A time-out
period longer than the character receive duration can be used by software to
indicate that a character was not received in the expected time and the
software can disable BRCLK.
Figure 13−13. Glitch Suppression, USART Activated
URXDx
URXS
t
τ
Majority Vote Taken
Przeglądanie stron 279
1 2 ... 275 276 277 278 279 280 281 282 283 284 285 ... 431 432

Komentarze do niniejszej Instrukcji

Brak uwag