Specifications

Chapter 3 - General Programming Issues CARROLL TOUCH
3-10 Touch System Programmer’s Guide
receive a command or whether it is busy. Table 3-2 shows the values of
Bit 0 of the Status Register.
If Bit 0 of the Status Register is 0, you may send a command to the touch
controller by performing an I/O write to the Data Register (Base
Address). If Bit 0 of the Status Register is 1, do not send a touch
command to the touch controller.
Receiving Touch Data from the HBC
The procedure used to receive data from the HBC differs depending on
which communication mode you are using.
Polling Mode
When using polling mode, the application software polls the Status
Register (Base Address + 1) to check if touch data is available in the
Data Register (Base Address).
Before reading the Data Register, you must first perform an I/O read of
the Status Register. Bit 1 of the Status Register indicates whether there
is touch data available in the Data Register. Table 3-3 shows the values
of Bit 1 of the Status Register.
If Bit 1 of the Status Register is 0, you may receive a byte of touch data
by performing an I/O read of the Data Register. If Bit 1 of the Status
Register is 1, there is no data available in the Data Register.
Table 3-2. Status Register Bit 0 Values
Bit 0 Description
0 Touch controller ready to receive command.
1 Touch controller busy.
Table 3-3. Status Register Bit 1 Values
Bit 1 Description
0 Touch data available.
1 No touch data available.