TTP258
TonTouchTM
Preliminary
Standard I/O Port
The standard input/output port has the I/O control register for switching
input or output mode and output data register stores the output data in output
mode. If control data=1 and output data=1, the I/O 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 PI is reading data
comes from PAD input data. The data register reading result will have the same
value with output register data. Software can performs a configuration (data=0,
changing the control 0 or 1) for open drain type that specifies suitable for key
scan application.
I/O control Data
Output data
Pull-up
No
Wake-up
No
0
X
0
1
1
1
No
No
Enable
Enable
X: don’t care the value
I/O control Data
MODE
Output mode
Input mode
PAD
0
1
Output Register data
Input data
Read PI
Read Input Data
Output Register data
PAD input data
0
1
Pull-High R
P
S
Data Bus
D
Q
I/O control Register Write
CK
QB
PR
S
P
D
Q
PAD
Output Data Register Write
Read PI
CK QB
N
M
U
X
0
Wake-up
1
Read
N
N
Figure IO-C: Standard I/O Port
16’/04/06
Page 30 of 44
Ver.: 1.2
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