TTP259
TonTouchTM
Preliminary
. IO Pad Cell Structure and Function Description
.. IO port with touch pad input
The input/output port has the IO control register for switching input or
output mode and data register stores the output data in output mode. If IO
control register=1 and output data=1, the IO port is programmed as input
with pull-up resistor and also actives the wake-up function. User intends to
read the port data with differed read instruction. The read PxI is reading data
comes from IO pad data. The data register reading result will have the same
value with output register data. Software can performs a configuration
(output data register=0, changing the IO control register 0 or 1) for open
drain type that specifies suitable for key scan application. An additional
feature supports the touch pad input.
Extern input
IO control data Output data
Pull-up
R
Wake-up
feature
No
Disable
Disable
0
1
1
X
X
0
1
X
No
No
No
Disable
Enable
No
Enable
No
Enable and touch
pad scan
X: don’t care the value
IO control data
IO pad
0
1
Output register data
IO pad input data
Read PxI
1
Read input data
IO pad data
2015/05/25
Page 49 of 81
Ver: 1.1
TTELEC [ TT Electronics ]
