Calibre UK UCA93 manual Int IOState

CALIBRE

3.3.21.Write_IO_Pin

Function specification	int Write_IO_Pin (int IONumber, int IOState)
Parameters are:int IONumber
	The number of the IO pin (0 or 1) to be driven
	int IOState
Parameters returned	The required state (0 or 1) of the selected IO pin
	int
	Returns a 0 if function successful.
Prerequisites	Returns 0x800D if the transfer timed out.
	None
Functional description	Two spare IO pins are available to drive external logic. IO0 is on PL1 pin 2 and
	is an open drain driver. When driven low it can sink up to 10mA, when high it is
	high impedance and cannot source current. A pullup resistor should be fitted to
	the desired rail which should not exceed +5V. IO1 is on PL1 pin 3 and is a
	complementary driver which can source or sink up to 10mA. Its logic levels are
	fixed at 0V and +5V nominal.

3.3.22.Read_IO_Pin

Function specification	int Read_IO_Pin (int IONumber)
Parameters are:int IONumber
Parameters returned	The number of the IO pin (0 or 1) to be read
	int
	Returns the state (0 or 1) of the chosen IO pin if function successful.
Prerequisites	Returns 0x800D if the transfer timed out.
	None
Functional description	Two spare IO pins are available which can be driven by external logic. IO0 is
	on PL1 pin 2 and IO1 is on PL1 pin 3. These pins are normally high impedance
	input unless specifically driven by the Write_IO_Pin function. They can be
	driven high or low by external logic then read by the Read_IO_Pin function.
	Normal 5V CMOS logic levels (0 < 1.5V, 1 > 3.5V) should be applied for reliable
	reading.

Issue 1.0	Page 14
01/07/03