Data Sheet

ISM14585-L35 Specification
DOC-DS-14585-201807-3.0
Confidential Inventek Systems
Page 62
9.10 Wake-Up Timer
The Wake-up timer can be programmed to wake up the ISM14585 from power down
mode after a pre-programmed number of GPIO events.
Each of the GPIO inputs can be selected to generate an event by programming the
corresponding WKUP_SELECT_Px_REG register. When all WKUP_SELECT_Px_REG
registers are configured to generate a wake-up interrupt, a toggle on any GPIO will
wake up the system.
• The input signal edge can be selected by programming the
WKUP_POL_Px_REG register.
• The block diagram illustrating the Wake-up function is shown in Figure 31.
Features
• Monitors any GPIO state change
• Implements debouncing time from 0ms up to 63ms
• Accumulates external events and compares the number to a programmed value
• Generates an interrupt to the CPU
Figure 31 Wake-Up Timer Block Diagram
A LOW to HIGH level transition on the selected input port, while
WKUP_POL_Px_REG[y] = 0, sets internal signal “key_hit” to ‘1’. This signal triggers the
event counter state machine as shown in Figure 31. The debounce timer is loaded with
value WKUP_CTRL_REG[WKUP_DEB_VALUE]. The timer counts down every 1ms. If
the timer reaches 0 and the “key_hit” signal is still ‘1’, the event counter will be
incremented.