S3C2416X RISC MICROPROCESSOR
ADC AND TOUCH SCREEN INTERFACE
22-3
2.2 FUNCTION DESCRIPTIONS
2.2.1 A/D Conversion Time
When the PCLK frequency is 50 MHz, the prescaler value is 49 and total 10-bit and 12-bit conversion time is
given:
A/D converter freq. = 50 MHz/(49+1) = 1 MHz
Conversion time = 1/(1MHz / (5cycles)) = 1/200 KHz = 5 us
NOTE
This A/D converter is designed to operate at maximum 5 MHz clock, so the conversion rate can go up to
1MSPS.
2.2.2 Touch Screen Interface Modes (AIN6 ~ AIN9)
1. Normal conversion mode (AUTO_PST = 0, XY_PST = 0)
The operation of this mode is identical with AIN0~AIN5’s. It can be initialized by setting the ADC Control
Register (ADCCON) and ADC touch screen control register (ADCTSC). All of the switches and pull-up
resister should be turned off (reset value 0x58 makes switches turn-off). The converted data can be read out
from ADC conversion data 0 register (ADCDAT0).
2. Separate X/Y position conversion mode (AUTO_PST = 0, XY_PST : contorl)
This mode consists of two states; one is X-position measurement state and the other is Y-position
measurement state.
X-position measurement state is operated as the following way; set XY_PST is ‘1’ and read out the converted
data (X-position) from ADCDAT0. The end of X-position conversion can be notified by interrupt (INT_ADC).
Y-position measurement state is operated as the following way; set XY_PST is ‘2’ and read out the converted
data (Y-position) from ADCDAT1. The end of Y-position conversion can be notified by interrupt (INT_ADC).
State
XP XM YP YM
X
-position measurement
VDDA_ADC
VSSA_ADC
AIN7
Hi-z
Y
-position measurement
AIN9 Hi-z
VDDA_ADC
VSSA_ADC
3. Auto(Sequential) X/Y position conversion mode (AUTO_PST = 1, XY_PST = 0)
Auto (sequential) X/Y position conversion mode is operated as the following. Touch screen controller
sequentially converts X-position and Y-position that is touched. After touch screen controller converts X-
position data to ADCDAT0 and then converts Y-position data to ADCDAT1, Touch screen interface generates
interrupt (INT_ADC). The measurement states are automatically changed.
Содержание S3C2416
Страница 33: ...S3C2416X RISC MICROPROCESSOR PRODUCT OVERVIEW 1 5 3 BLOCK DIAGRAM Figure 1 1 S3C2416X Block Diagram ...
Страница 38: ...PRODUCT OVERVIEW S3C2416X RISC MICROPROCESSOR 1 10 153 AIN 1 U14 195 EINT 10 GPG2 K15 237 SDATA 14 C18 ...
Страница 122: ...BUS MATRIX EBI S3C2416X RISC MICROPROCESSOR 3 4 NOTES ...
Страница 204: ...DMA CONTROLLER S3C2416X RISC MICROPROCESSOR 8 18 NOTES ...
Страница 284: ...WATCHDOG TIMER S3C2416X RISC MICROPROCESSOR 11 6 NOTES ...
Страница 320: ...REAL TIME CLOCK S3C2416X RISC MICROPROCESSOR 13 16 NOTES ...
Страница 344: ...UART S3C2416X RISC MICROPROCESSOR 14 24 NOTES ...
Страница 380: ...USB2 0 DEVICE S3C2416X RISC MICROPROCESSOR 16 34 NOTES ...
Страница 432: ...2D S3C2416X RISC MICROPROCESSOR 18 38 NOTES ...
Страница 446: ...HS_SPI CONTROLLER S3C2416X RISC MICROPROCESSOR 19 14 NOTES ...
Страница 455: ...S3C2416X RISC MICROPROCESSOR HSMMC CONTROLLER 20 9 4 9 SD COMMAND ISSUE SEQUENCE Figure 20 9 Timeout Setting Sequence ...
Страница 604: ...S3C2416X RISC MICROPROCESSOR S3C2416X RISC MICROPROCESSOR 23 22 NOTES ...
Страница 638: ...PCM AUDIO INTERFACE S3C2416X RISC MICROPROCESSOR 25 18 NOTES ...
Страница 653: ...S3C2416X RISC MICROPROCESSOR ELECTRICAL DATA 26 15 Figure 26 14 SDRAM READ WRITE Timing Trp 2 Trcd 2 Tcl 2 DW 16 bit ...
Страница 670: ...ELECTRICAL DATA S3C2416X RISC MICROPROCESSOR 26 32 NOTES ...
Страница 672: ...MECHANICAL DATA S3C2416X RISC MICROPROCESSOR 30 2 Figure 27 2 330 FBGA 1414 Package Dimension 2 Bottom View ...