AS3722 datasheet(73/199 Pages) AMSOSRAM

73 / 199 page

Page 72

ams Datasheet

Document Feedback

[v1-01] 2015-Sep-07

AS3722 − Detailed Descriptions- System Functions

Watchdog

Description

The purpose of the watchdog is to detect a deadlock of the

software. If the watchdog is active, it must receive a continuous

trigger signal within a programmable time window. If there is

no signal anymore for a certain time period from a defined pad

or special serial interface bit, it starts either a complete reset

cycle or initiates the power off sequence.

The watchdog is highly configurable by the following register

bits:

• The complete block can be switched on by wtdg_on = 1

and off by wtdg_on = 0.

• The watchdog time window is defined by the register

wtdg_timer between 1s and 128s.

• The trigger signal can be either triggered by setting

wtdg_sw_sig or using a HW signal on one of the GPIO pins

(gpioX_iosf=9).

• If the watchdog expires, the system waits another second

before reacting according to wtdg_mode (OTP setting)

• 0: interrupt 8s before the watchdog expires, only if the

interrupt is not masked

• 1: reset_cycle with re-start

• 2: power_off

• 3: reset_cycle with re-start up to two times, if the

watchdog expires a third time the systems goes into

power_off

• Whether the watchdog caused a reset can be seen in the

reset_reason.

Figure 68:

Watchdog Timing

Watchdog Timing: Shows the basic timing relations of the watchdog counter and related signals.

n-1

n-2

n-1

watchdog

counter

counter set to n

seconds

counter reset by

setting bit

wtdg_sw_sig

wdtg_sw_sig

XINT

interrupt triggered

if enalbed

watchdog expires

action according

to wtdg_mode

AS3722 bảng dữ liệu(PDF) 73 Page - ams-OSRAM AG

AS3722 bảng dữ liệu(HTML) 73 Page - ams-OSRAM AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

bảng dữ liệu tải về

Link URL