Freescale Semiconductor MCF52277 Reference Manual page 498

Touchscreen Controller/Analog-to-Digital Converter
BIACTRL
SELREFP
SELREFN
SELINP
PENDOWN_IRQ
ASPE
DATA_READY_IRQ
a) Pen-down is detected by the touchscreen controller and pen-down interrupt is initiated.
b) MCU clears/masks pen-down interrupt.
c) MCU configures ASP_SET for X measurement.
d) MCU sets ASPE to initiate X-coordinate conversion.
e) Conversion completes, result is written into the FIFO, and the data ready interrupt occurs.
f) MCU clears ASPE to prepare for the next operation.
g) MCU reads out the X measurement result, and data ready interrupt is cleared automatically.
h) MCU changes the configuration to Y measurement.
i) MCU sets ASPE again to initiate Y-coordinate conversion.
j) Conversion complete, the result is written into FIFO, and the data ready interrupt occurs.
k) MCU clears ASPE to prepare for the next operation.
l) MCU reads out the Y measurement result, and data ready interrupt is cleared automatically.
BIACTRL
SELREFP
SELREFN
SELINP
ASPE
DATA_READY_IRQ
Figure 22-11. Manual Mode For General-Purpose ADC Application
a) MCU sets ASP_SET to configuration 1.
b) MCU sets ASPE to initiate the conversion.
c) Conversion completes, result is written into FIFO, and data ready interrupt occurs.
d) MCU clears ASPE to prepare for the next operation.
e) MCU reads out the conversion result and the data ready interrupt is cleared automatically.
f) MCU changes ASP_SET to configuration 2.
g) MCU sets ASPE to initiate the conversion.
h) Conversion completes, result is written into FIFO, and data ready interrupt occurs.
i) MCU clears ASPE to prepare for the next operation.
j) MCU reads out the conversion result and the data ready interrupt is cleared automatically.
22-18
Pen detect X measurement setting
c
a b
Figure 22-10. Manual Mode For Touchscreen Application
Configuration 1
a
b
MCF52277 Reference Manual, Rev. 1
d f
e g
f
d g
c e
Y measurement setting
h
i k
j
Configuration 2
i
h j
Freescale Semiconductor
l