Z8FMC16100 Series Flash MCU
Product Specification
115
7. Execute an EI instruction to enable interrupts.
The LIN-UART is now configured for interrupt-driven data transmission. Because the
LIN-UART Transmit Data Register is empty, an interrupt is generated immediately. When
the LIN-UART Transmit interrupt is detected, and there is transmit data ready to send, the
associated interrupt service routine (ISR) performs the following:
1. If in MULTIPROCESSOR mode, write the LIN-UART Control 1 Register to select
the outgoing address bit:
Set the Multiprocessor Bit Transmitter (MPBT) if sending an address byte, clear it if
sending a data byte.
2. Write the data byte to the LIN-UART Transmit Data Register. The transmitter auto-
matically transfers the data to the Transmit Shift register and transmits the data.
3. Execute the IRET instruction to return from the interrupt-service routine and wait for
the Transmit Data Register to again become empty.
If a transmit interrupt occurs and there is no transmit data ready to send the interrupt-ser-
vice routine will execute the IRET instruction. When the application does have data to
transmit, software can set the appropriate interrupt request bit in the Interrupt Controller to
initiate a new transmit interrupt. Another alternative would be for software to write the
data to the Transmit Data Register instead of invoking the interrupt-service routine.
Receiving Data using the Polled Method
Follow these steps to configure the LIN-UART for polled data reception:
1. Write to the LIN-UART Baud Rate High and Low Byte registers to set the appropriate
baud rate.
2. Enable the LIN-UART pin functions by configuring the associated GPIO port pins for
alternate function operation.
3. Write to the LIN-UART Control 1 Register to enable MULTIPROCESSOR mode
functions, if appropriate.
4. Write to the LIN-UART Control 0 Register to:
a. Set the receive enable bit (REN) to enable the LIN-UART for data reception
b. If multiprocessor mode is not enabled, enable parity, if appropriate, and select
either even or odd parity.
5. Check the RDAbit in the LIN-UART Status 0 register to determine if the Receive Data
Register contains a valid data byte (indicated by a 1). If RDAis set to 1 to indicate
available data, continue to Step 6. If the Receive Data Register is empty (indicated by
a 0), continue to monitor the RDA bit awaiting reception of the valid data.
PS024604-1005
P R E L I M I N A R Y
Receiving Data using the Polled Method
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