TMP92CF26AXBG Toshiba, TMP92CF26AXBG Datasheet - Page 585

• Manufacturer Part Number: TMP92CF26AXBG
• Description: Microcontrollers (MCU) TLCS-900/H1 ROMLESS 144KB RAM
• Manufacturer: Toshiba

Specifications of TMP92CF26AXBG

• Processor Series: TLCS-900
• Core: 900/H
• Data Bus Width: 16 bit
• Program Memory Type: ROM
• Program Memory Size: 8 KB
• Data Ram Size: 144 KB
• Interface Type: I2C, I2S, UART, USB
• Maximum Clock Frequency: 80 MHz
• Number Of Programmable I/os: 136
• Number Of Timers: 10
• Maximum Operating Temperature: + 50 C
• Mounting Style: SMD/SMT
• Package / Case: FBGA-228
• Development Tools By Supplier: BM1040R0A, BM1055R0B, SW96CN0-ZCC, SW00MN0-ZCC
• Minimum Operating Temperature: 0 C
• On-chip Adc: 10 bit, 6 Channel
• Lead Free Status / Rohs Status: Details

3.20.4
Touch screen resistor : Rty (Rtx)
The resistance depends on
ON-resistor: Rmy (Rmx)
ON-resistor: Rpy (Rpx)
measuring following the procedure below:
position measurement above can be determined with the ratio between the ON resistance
value of the switch in the TMP92CF26A and the resistance value in the touch screen as
shown in Figure 3.20.5.
will be neither 3.3V nor 0.0V.
during designing. It is also recommended that an average taken from several AD
conversions performed if required be adopted as the final correct value.
X/Y position measuring procedure
During the routine of pen-touch and INT4 interrupt generation, execute a pen position
<X position coordinate measurement>
The above analog voltage which is input to AN3 and AN2 pins during the X and Y
Therefore, even when touching an end area on the touch screen, the analog input voltage
Note that the rate of each resistance varies. Remember to take this into consideration
<Y position coordinate measurement>
the touch screen.
PG3/MY/AN3 pin.
using the AD converter.
PG2/MX/AN2 pin.
AD converter.
SMY (SMX)
Make the SPX and SMX switches ON, and the SPY and SMY switches OFF.
With this setting, an analog-voltage that shows the X position will be input to the
The X-position coordinate can be measured by converting this voltage to digital code
Make the SPY and SMY-switches ON, and the SPX and SMX switches OFF.
With this setting, an analog voltage that shows the Y position will be input to the
The Y position can be measured by converting this voltage to digital code using the
SPY (SPX)
typ.10Ω
typ.10Ω
AVCC=3.3V
Figure 3.20.5 Calculation analog voltage
R1
R2
Touch-point
92CF26A-584
AN2 (AN3)-pin
[Analog input voltage to theAN2 and AN3 pins: Formula to calculate E1]
E1 = ((100+10) / (10+400+100+10) × 3.3
Note1: An X-coordinate position can be calculated in the same way
Note2: Rty = R1+R2.
Ex.) Where AVCC=3.3V, Rpy=Rmy=10Ω, R1=400Ω and R2=100Ω
E1 = ((R2+Rmy) / (Rpy+Rty+Rmy)) × AVCC [V]
though above formula is for Y-coordinate position.
= 0.698V
TMP92CF26A
2007-11-21