Freescale Semiconductor MCF52277 Reference Manual page 509

BIACTRL
SELREFP
SELREFN
SELINP
ASPE
FIFO_WM_IRQ
a) ASP configuration is complete, and waits for ASPE to be set.
b) MCU sets ASPE to initiate the calibration process.
c) FIFO watermark interrupt occurs when the water mark level is equal to the amount of data for
one round of calibration.
d) ASP clears the FIFO watermark interrupt by uploading the data from the FIFO.
e) Steps c and d repeat.
f) The FIFO watermark interrupt for the last round of calibration occurs.
g) ASP clears ASPE to stop the calibration.
h) ASP uploads the last round of calibration data from the FIFO, which clears the FIFO watermark
interrupt.
If MIDLECNT is equal to zero, remove the IDLE measurement phase.
If RIDLECNT is equal to zero, remove the IDLE round phase.
Freescale Semiconductor
R CALA M
1
I DLE
M easur e I DLE
Figure 22-26. Touchscreen Calibration Auto, Part 2
NOTE
MCF52277 Reference Manual, Rev. 1
Touchscreen Controller/Analog-to-Digital Converter
CALA M CALA
i n
M easur e I DLE M easur e
R
I DLE
I DLE
g
f h
22-29