13892 datasheet(60/158 Pages) FREESCALE

60 / 158 page

FUNCTIONAL DEVICE OPERATION

OPERATING MODES

Analog Integrated Circuit Device Data



Freescale Semiconductor

MC13892

GLOBAL SYSTEM RESTART

A global system reset can be enabled through the GLBRSTENB SPI bit. The global reset on the MC13892A/C versions is

active low so it is enabled when the GLBRSTENB = 0. In the MC13892B/D versions global reset is active high and it is enabled

when the GLBRSTENB = 1. When global reset is enabled and the PWRON3 button is held for 12 seconds, the system will reset

and the following actions will take place:

•

Power down

•

Disable the charger

•

Reset all the registers including the RTCPORB registers

•

Power back up after the difference between the 12 sec timer, and when the user releases the button as the power off time

(for example, if the power button was held for 12.1 s, then the time that the IC would be off would be only 100 mS)

If PWRON3 is held low for less than 12 seconds, it will act as a normal PWRON pin. This feature is enabled by default in the

MC13892A/C versions, and disabled by default in the MC13892B/D versions.

CLK32KMCU CLOCK DRIVER CONTROL THROUGH STATES

As described previously, the clocking behavior is influenced by the state machine is in and the setting of the clocking related

SPI bits. A summary is given in Table 23 for the clock output CLK32KMCU.

TURN ON EVENTS

When in Off mode, the MC13892 can be powered on via a Turn On event. The Turn On events are listed in Table 24. To

indicate to the processor what event caused the system to power on, an interrupt bit is associated with each of the Turn On

events. Masking the interrupts related to the turn on events will not prevent the part to turn on, except for the time of day alarm.

Power Button Press

PWRON1, PWRON2, or PWRON3 pulled low with corresponding interrupts and sense bits PWRON1I, PWRON2I, or

PWRON3I, and PWRON1S, PWRON2S, or PWRON3S. A power on/off button is connected here. The PWRONx can be

hardware debounced through a programmable debouncer PWRONxDBNC[1:0] to avoid the application to power up upon a very

short key press. In addition, a software debounce can be applied. BP should be above UVDET. The PWRONxI interrupt is

generated for both the falling and the rising edge of the PWRONx pin. By default, a 30 ms interrupt debounce is applied to both

falling and rising edges. The falling edge debounce timing can be extended with PWRONxDBNC[1:0] as defined in the following

table. The PWRONxI interrupt is cleared by software or when cycling through the Off mode.

Table 23. CLK32MCU Control Logic Table

Mode

DRM

CLK32KMCUEN

USEROFFCLK

Clock Output CLK32KMCU

Off, Memory Hold, Internal MEMHOLD PCUT

Disabled

Enabled

On, Cold Start, Warm Start, Watchdog, User Off Wait

Disabled

Enabled

User Off

Disabled

Enabled

Table 24. PWRONx Hardware Debounce Bit Settings

Bits

State

Turn On Debounce (ms)

Falling Edge INT Debounce (ms)

Rising Edge INT Debounce (ms)

PWRONxDBNC[1:0]

31.25

125

31.25

750

31.25

Notes

48.

The sense bit PWRONxS is not debounced and follows the state of the PWRONx pin

13892 Datasheet(PDF) 60 Page - Freescale Semiconductor, Inc

13892 Datasheet(HTML) 60 Page - Freescale Semiconductor, Inc

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

Datasheet Download

Link URL