Rainbow Electronics AT90S8515 - Manual (Page 57)

57
AT90S8515
0841G–09/01
BAUD Rate Generator The baud rate generator is a frequency divider that generates baud rates according to
the following equation:
• BAUD = Baud rate
• f
CK
= Crystal Clock frequency
• UBRR = Contents of the UART Baud Rate register, UBRR (0 - 255)
For standard crystal frequencies, the most commonly used baud rates can be generated
by using the UBRR settings in Table 17. UBRR values that yield an actual baud rate dif-
fering less than 2% from the target baud rate are boldface in the table. However, using
baud rates that have more than 1% error is not recommended. High error ratings give
less noise immunity.
BAUD
f
CK
16(UBRR 1) +
------------------------------------- =