Z8F640x/Z8F480x/Z8F320x/Z8F240x/Z8F160x
Z8 Encore!®
82
Receiving Data using the Polled Method
Follow these steps to configure the UART for polled data reception:
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. Write to the UART Control 1 register to enable Multiprocessor (9-bit) mode functions,
if desired.
4. Write to the UART Control 0 register to:
–
–
Set the receive enable bit (REN) to enable the UART for data reception
Enable parity, if desired, and select either even or odd parity.
5. Check the RDAbit in the 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.
6. Read data from the UART Receive Data register. If operating in Multiprocessor (9-bit)
mode, first read the Multiprocessor Receive flag (MPRX) to determine if the data was
directed to this UART before reading the data.
7. Return to Step 6 to receive additional data.
Receiving Data using the Interrupt-Driven Method
The UART Receiver interrupt indicates the availability of new data (as well as error con-
ditions). Follow these steps to configure the UART receiver for interrupt-driven operation:
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 Receiver interrupt and set
the desired priority.
5. Clear the UART Receiver interrupt in the applicable Interrupt Request register.
6. Write to the UART Control 1 register to enable Multiprocessor (9-bit) mode functions,
if desired.
PS017610-0404
UART
ZILOG [ ZILOG, INC. ]
