TTP258
Preliminary
TonTouchTM
TPCHS0
TPEN3~0
0001
TPCHS1
TPCHS2
Channel Enable State
TPEN7~4
0000
TPEN9~8
TP0
TP1
TP2
TP3
TP4
TP5
TP6
TP7
TP8
TP9
00
00
00
00
00
00
00
00
01
10
0010
0000
0100
0000
1000
0000
0000
0001
0000
0010
0000
0100
0000
1000
0000
0000
0000
0000
When TPCHS0 is writing, TPCTL will be set TP RUN mode, and touchpad
begin to scan touchpad
Users can enable multi-channel by setting corresponding bit 1, which will
turn on all enable channel at the same time.
TPCTL[212H]: Touch pad control register [R/W], default value [0000]
Register
Bit Name
Read/Write
Bit3
Bit2
TPCTL2
R/W
Bit1
TPCTL1
R/W
Bit0
TPCTL0
R/W
-
-
TPCTL2~TPCTL0: Touch pad control selector
As program writes the TPCTL register hardware automatically discharges the
external capacitor and enables the sensor clock input until period end.
TPCTL2 ~ TPCTL0
Channel Enable State
000
001
010
011
100
101
110
111
TP STOP
TP RUN
-
Discharge
Inner Key
-
-
-
TP STOP: STOP the touch pad feature and release pad for IO port
TP RUN: TP RUN is touchpad scan start signal, its scan the channel by TPCHS2~0 select.
Inner Key: Select switch select Inner Key. Inner Key is reference Key, this pad is no bounding
to package.
Discharge: Discharge can hold touchpad in discharge state, to avoid discharge time too short.
As touch pad analog switch keeps on, the relative IO port should be disabled
as tri-state by hardware.
In user selection table, the available touch pads will be generated a ROM
code in option ROM.
16’/04/06
Page 40 of 44
Ver.: 1.2
TTELEC [ TT Electronics ]
