TTP258
TonTouchTM
Preliminary
I/O port with internal output & external input
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. If enable internal output, the internal output
will control by output data (on/off) and outputs to PAD.
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
Internal output
PAD
0
0
1
enable
disable
X
Output internal data
Output Register data
PAD input data
X: don’t care the value
Read PI
Mode
Output mode
Input mode
Read Input Data
Output Register data
PAD input data
0
1
Pull-up
Data Bus
S
D
Q
P
CK
QB
I/O ctrl Register Write
PR
S
P
D
Q
Data Register Write
Read PI
CK
QB
N
PAD
M
U
X
Read
Wake-up
N
N
Timer/counter external clock
External interrupt
Internal output signal (PWM)
Output enable
Figure IO-D: Standard I/O Port with internal output signal & external input
16’/04/06
Page 31 of 44
Ver.: 1.2
TTELEC [ TT Electronics ]
