Z8F6421PM020SC Datasheet, PDF (121/299 Pages) Zilog, Inc. – High Performance 8-Bit Microcontrollers Z8 Encore-R 64K Series

Z8 Encore!^® 64K Series
Product Specification
101
– Set or clear the CTSE bit to enable or disable control from the remote receiver
using the CTS pin.
5. Check the TDRE bit in the UART Status 0 register to determine if the Transmit Data
register is empty (indicated by a 1). If empty, continue to Step 6. If the Transmit Data
register is full (indicated by a 0), continue to monitor the TDRE bit until the Transmit
Data register becomes available to receive new data.
6. Write the UART Control 1 register to select the outgoing address bit.
7. Set the MULTIPROCESSOR Bit Transmitter (MPBT) if sending an address byte, clear
it if sending a data byte.
8. Write the data byte to the UART Transmit Data register. The transmitter automatically
transfers the data to the Transmit Shift register and transmits the data.
9. If desired and MULTIPROCESSOR mode is enabled, make any changes to the
MULTIPROCESSOR Bit Transmitter (MPBT) value.
10. To transmit additional bytes, return to Step 5.
Transmitting Data using the Interrupt-Driven Method
The UART transmitter interrupt indicates the availability of the Transmit Data register to
accept new data for transmission. Follow these steps to configure the UART for interrupt-
driven data transmission:
1. Write to the UART Baud Rate High and Low Byte registers to set the desired baud
rate.
2. Enable the UART pin functions by configuring the associated GPIO Port pins for
alternate function operation.
3. Execute a DI instruction to disable interrupts.
4. Write to the Interrupt control registers to enable the UART Transmitter interrupt and
set the desired priority.
5. If MULTIPROCESSOR mode is desired, write to the UART Control 1 register to
enable MULTIPROCESSOR (9-bit) mode functions.
6. Set the MULTIPROCESSOR Mode Select (MPEN) to Enable MULTIPROCESSOR
mode
7. Write to the UART Control 0 register to:
– Set the transmit enable bit (TEN) to enable the UART for data transmission
– Enable parity, if desired and if multiprocessor mode is not enabled, and select
either even or odd parity
– Set or clear the CTSE bit to enable or disable control from the remote receiver via
the CTS pin
PS019915-1005
UART