ZLF645 MAXIM [Maxim Integrated Products], ZLF645 Datasheet - Page 96

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

19-4572; Rev 0; 4/09
Caution:
Transmitting Data Using Interrupt-Driven Method
4. Check the Transmit Status register bit, UST[2], to determine if the Transmit Data 
5. Write the data byte to the UART Transmit Data register,
6. To transmit additional bytes, return to
7. Before disabling the transmitter, read the transmit completion status bit, UST[1]. If
The UART transmitter interrupt indicates the availability of the Transmit Data register to
accept new data for transmission.
Follow the steps below to configure the UART for interrupt-driven data transmission:
1. Write to the BCNST register to set the appropriate baud rate.
2. Write 0 to bit 6 of the P01M register.
3. Execute DI instruction to disable interrupts.
4. Write to the Interrupt Control registers to enable the UART Transmitter interrupt and
5. Write to the UART Control register to:
6. Execute an EI instruction to enable interrupts as the transmit buffer is empty, an 
7. Write the data byte to the UART Transmit Data register. The transmitter automatically
8. Execute the IRET instruction to return from the interrupt service routine (ISR) and
Data written while the transmit enable bit is clear (UCTL[7]=0) will not be transmitted.
Data written while the transmit data status bit is clear (UST[2]=0) overwrites the
previous value written, so the previous written value will not be transmitted. Disabling
the UART transmitter while the transmit completion status bit is clear (UST[1]=0) can
corrupt the byte being transmitted.
register is empty (indicated by 1). If empty, continue to
register is full (indicated by 0), continue to monitor the UST[2] bit until the Transmit
Data register is available to receive new data.
automatically transfers the data to the internal transmit shift register and transmits the
data.
UST[1]=0, continue to monitor the bit until it changes to 1, which indicates that all
data in the Transmit Data and internal shift registers has been transmitted.
set the appropriate priority.
(a) Set the transmit enable bit (UCTL bit 7) to enable the UART for data transmission.
(b) Enable parity, if appropriate, and select either even- or odd-parity.
interrupt is immediately executed.
transfers the data to the Internal Transmit Shift register and transmits the data.
wait for the Transmit Data register to again become empty.
Step
4.
ZLF645 Series Flash MCUs
0F1h
Step
Product Specification
. The transmitter 
6. If the Transmit Data
Operation

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