Samsung S3C6400X User Manual page 1140

KEYPAD INTERFACE
DEBOUNCING FILTER
The debouncing filter is supported for keypad interrupt of any key input. The filtering width is approximately
62.5usec ("FLT_CLK" two-clock, when the FLT_CLK is 32 KHz). The keypad interrupt (key pressed or key
released) to the CPU is an ANDed signal of the all row input lines after filtering.
FILTER_IN
FILTER_OUT
Filter width : FCLK two-clock
Filter Clock(FCLK) is a FLT_CLK or the division of that clock.
FLT_CLK is come from System Controller, RTCCLK(32Khz) or
OSCIN(ex:12Mhz)
Preliminary product information describe products that are in development,
40-2
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
Figure 40-2 Internal Debouncing Filter Operation
S3C6400X III RISC MICROPROCESSOR