EZ80F920120MOD Zilog, EZ80F920120MOD Datasheet - Page 122

• Manufacturer Part Number: EZ80F920120MOD
• Description: MODULE EZ80F92 512K 20MHZ
• Manufacturer: Zilog

Specifications of EZ80F920120MOD

• Module/board Type: Development Module
• Processor Series: EZ80F92x
• Core: eZ80
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 1 MB
• Interface Type: Cable
• Maximum Clock Frequency: 20 MHz
• Operating Supply Voltage: 0 V to 3.3 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Package / Case: LQFP
• Development Tools By Supplier: eZ80F920200ZCOG
• Minimum Operating Temperature: 0 C
• For Use With/related Products: eZ80F92
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 269-3157; EZ80F920120MOD

PS015308-0404
UART Recommended Usage
The following is the standard sequence of events that occur in the eZ80F92 device using
the UART. A description of each follows.
•
•
•
Module Reset
Upon reset, all internal registers are set to their default values. All command status regis-
ters are programmed with their default values, and the FIFOs are flushed.
Control Transfers
Based on the requirements of the application, the data transfer baud rate is determined and
the BRG is configured to generate a 16X clock frequency. Interrupts are disabled and the
communication control parameters are programmed in the UARTx_LCTL register. The
FIFO configuration is determined and the receive trigger levels are set in the
UARTx_FCTL register. The status registers, UARTx_LSR and UARTx_MSR, are read,
and ensure that none of the interrupt sources are active. The interrupts are enabled (except
for the transmit interrupt) and the application is ready to use the module for transmission/
reception.
Data Transfers
Transmit.
immediately expected in response. The application reads the UARTx_IIR register and
determines whether the interrupt occurs due to an empty UARTx_THR register or due to a
completed transmission. Upon this determination, the application writes the pertinent
transmit data bytes to the UARTx_THR register. The number of bytes that the application
writes depends on whether or not the FIFO is enabled. If the FIFO is enabled, the applica-
tion can write 16 bytes at a time. If not, the application can write one byte at a time. As a
result of the first Write, the interrupt is deactivated. The processor then waits for the next
interrupt. When the interrupt is raised by the UART module, the processor repeats the
same process until it exhausts all of the data for transmission.
To control and check the modem status, the application sets up the modem by writing to
the UARTx_MCTL register and reading the UARTx_MCTL register before starting the
process mentioned above.
Receive.
RxD input signal. When an interrupt is raised by the UART module, the application reads
the UARTx_IIR register and determines the cause for the interrupt. If the cause is a line
status interrupt, the application reads the UARTx_LSR register, reads the data byte and
Module reset
Control transfers to configure UART operation
Data transfers
The receiver is always enabled, and it continually checks for the start bit on the
To transmit data, the application enables the transmit interrupt. An interrupt is
P R E L I M I N A R Y
Universal Asynchronous Receiver/Transmitter
Product Specification
eZ80F92/eZ80F93
110