ZLF645 MAXIM [Maxim Integrated Products], ZLF645 Datasheet - Page 102

• Manufacturer Part Number: ZLF645
• Description: Flash MCUs with Learning Amplification
• Manufacturer: MAXIM [Maxim Integrated Products]

19-4572; Rev 0; 4/09
Follow the steps below to configure the BRG as a timer with interrupt on time-out:
1. Disable the UART by clearing the receive and transmit enable bits, UCTL[7:6] to 0.
2. Load the appropriate 8-bit count value into the UART Baud Rate Generator Constant
3. Enable the Baud Rate Generator timer function and associated interrupt by setting the
Table 42
frequencies.
Table 42. BCNST Register Settings Examples
Target UART Data
Rate (baud)
2400
4800
9600
19200
register. The count frequency is the system clock frequency (in Hz) divided by 16.
Baud Rate Generator bit (UCTL bit 0) in the UART Control register to 1. When 
configured as an 8-bit timer, the count value, instead of the reload value, is read, and
the counter begins counting down from its initial programmed value. On timing out
(reaching a value of 1), if the time-out interrupt is enabled, an interrupt will be 
produced. The counter will then reload its programmed start value and begin counting
down again.
lists a number of BCNST register settings at various baud rates and system clock
System Clock = 4 MHz, 
Crystal Clock = 8 MHz
BCNST = 01101000 
Actual baud rate = 2403
BCNST = 00110100 
Actual baud rate = 4807
BCNST = 00011010 
Actual baud rate = 9615
BCNST = 00001101 
Actual baud rate = 19230
System Clock = 3 MHz, 
Crystal Clock = 6 MHz
BCNST = 01001110 
Actual baud rate = 2403
BCNST = 00100111 
Actual baud rate = 4807
BCNST = 00010100 
Actual baud rate = 9375
BCNST = 00001010 
Actual baud rate = 18750
ZLF645 Series Flash MCUs
Product Specification
Operation
94