GR64 Integrators Manual
Page: 60/104
This document is the sole and exclusive property of WAVECOM. Not to be distributed or divulged without prior written agreement.
Ce document est la propriété exclusive de WAVECOM. Il ne peut être communiqué ou divulgué à des tiers sans son autorisation préalable
UART1 is a full featured Universal Asynchronous Receiver Transmitter providing full-
duplex asynchronous communication.
UART1 has the following features:
•
32 bytes of FIFO for both receive and transmit
•
FIFO threshold interrupts
•
1 start bit, 7 or 8 data bits, 1 optional parity bit, 1 or 2 stop bits
•
Programmable baud rate
•
Auto-configuration mode with auto-baud and auto-format operation
•
Hardware flow control
•
Software flow control.
Depending upon the user application, some, all, or none of the control signals may be
needed. Each of the control signals can alternatively be configured as a general
purpose IO. When hardware flow control is not used in communications between the
application and the Wireless CPU, some applications may require RTS and CTS to be
connected to each other at the Wireless CPU. Users should familiarize themselves
with the specific implementation of their UART.
The GR64 has a feature in which sleep (lower power) mode can be controlled through
a special handshake protocol using hardware flow control. Details of this protocol
and the AT commands associated with it are contained in a special Application Note,
obtainable through the normal customer support channel.
UART1 converted signals, together with GND, DTM1 and DFM1 form a 9-pin RS232
data port.
The electrical characteristic of this level-shifted signal is described in section 5.3.1.1.
UART1 signals replicate a 9-pin RS232 (V.24) serial port. However, UART1 signal
levels are not compliant with the RS232 (V.28) standard. Conversion between the
Wireless CPU CMOS levels and RS232 levels can be achieved using a standard
interface IC, such as the Maxim Integrated Products MAX3237. The relationship
between the levels is shown in the following table:
DTM, DFM
RI,RTS,CTS,DSR,DTM,DCD
RS232 level
GR64 level
1
OFF
<-3V
VREF
0
ON
>+3V
0 V
