Echelon I/O Model Reference for Smart Transceivers and Neuron Chips - Manual (Page 111)

I/O Model Reference 101
If you do not specify the #pragma specify_io_clock compiler directive, the
compiler uses a default I/O clock rate of 10 MHz.
Syntax
IO_8 sci [baud ( const-expr )] [twostopbits] [parity ( parity-expr )] io-object-name ;
baud (
const-expr )
Optionally specifies the serial bit rate through use of the enumeration values
found in the <io_types.h> include file. These enumeration values are:
• SCI_300
• SCI_600
• SCI_1200
• SCI_2400
• SCI_4800
• SCI_9600
• SCI_19200
• SCI_38400
• SCI_57600
• SCI_115200
The enumeration values select serial bit rates of 300, 600, 1200, 2400, 4800,
9600, 19200, 38400, 57600, and 115200, respectively. This clause is optional
in the declaration, but, if omitted, the io_set_baud( ) function must be used.
These bit rates are accurate for devices running at input or system clock
rates that are a multiple of 2.5 MHz. Devices using the 6.5536 MHz clock
rate can be inaccurate (off by more than 3%) at baud rates of 38400 and
higher because the bit rate divisor has been optimized for input clocks that
are a multiple of 2.5 MHz.
twostopbits
Set this option to use two stop bits. By default, there is one stop bit.
You cannot use two stop bits if you also specify even or odd parity. That is, to
use two stop bits, you must specify __parity(none).
This keyword is not supported for Series 5000 devices.
__parity ( parity-expr )
Specifies optional parity for the serial communications. A parity bit ensures
that the number of “1” bits between the start and stop bits is always even or
odd. Using parity allows you to perform error checking of the
communications channel.
The
parity-expr can be one of the following values: none, odd, or even.
__parity(none) is the default.
The use of parity is supported only for Series 5000 devices.