Issue
155 June 2003
Encore!
Zilog's
Z8 Flash Memory-Based Micro
COMMUNICATION
The
Z8 Encore! product family contains two fully independent
universal asynchronous receiver/transmitters (UART).
The UART is a full-duplex communication channel capable
of handling asynchronous data transfers using an 8-bit
data mode with selectable parity and 1 or 2 stop bits.
It consists of three primary functional blocks: transmitter,
receiver, and data rate generator.
The
transmitter and receiver function independently. They
have separate enables and interrupts but share the same
data rate and data format. Error checking provides feedback
for framing, parity, overrun errors, and break detection.
Each 16-bit data rate generator (BRG) can be used as
a general timer if the UART function isn’t needed. The
UART also supports the 9-bit multiprocessor Addressing
mode.
Infrared
endecs are integrated with each UART to allow easy communication
between the Z8 Encore! and the IrDA physical layer specification,
version 1.3-compliant infrared transceivers (see Figure
3). Infrared communication provides secure, reliable,
low-cost, point-to-point communication between PCs,
PDAs, cell phones, printers, and other infrared-enabled
devices.
|
(Click
here to enlarge)
|
Figure
3—Integrated infrared encoder/decoders bridge the
gap between the UART and external IR transmitter/receiver
components. Few external parts are required for
IR communication. |
The
serial peripheral interface (SPI) is a synchronous interface
that allows several SPI-type devices to be interconnected.
SPI-compatible devices include EEPROMs, A/D converters,
and ISDN devices. A dedicated data rate generator can
supply synchronous clocking for SPI Master mode. The
full-duplex, synchronous, character-oriented communication
uses a four-wire interface to supply data in, data out,
clock, and slave (chip) select. You have full control
of the polarity of the clock pulse as well as the sampling-edge
selection.
The
Z8 Encore! also supports I2C Master-Only mode, which
consists of two bidirectional bus lines: a serial data
signal (SDA) and a serial clock signal (SCL). The I2C
controller operates in both 7- and 10-bit address modes
at a maximum data rate of 400 kbps.
