PC87360 datasheet(74/168 Pages) NSC

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3.0 System Wake-Up Control (SWC) (Continued)

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Four Wake-Up Extension Enable registers (WK_X1EN0, 1 and WK_X2EN0, 1) hold two configuration bits for each of the 16

events to control the wake-up mode for each one of them. Figure 9 illustrates the Wake-Up Mode Control (Extension) mech-

anism.

Figure 9. Wake-Up Mode Control (Extension) Mechanism

In addition to monitoring various system events, the SWC operates several general-purpose I/O (GPIO) pins powered by

VSB. Two runtime data registers (SB_GPDO0 and SBGPDI0) hold a Data Out bit and a Data In bit for each VSB powered

GPIO pin. In addition, each GPIO pin has a dedicated configuration register that controls its characteristics. These configu-

ration registers are accessed via a set of Standby GPIO Pin Select and Pin Configuration registers (SBGPSEL and SBG-

PCFG). For a detailed description of the VSB powered GPIO pins, see Section 3.4.28.

The SWC logic is powered by VSB. The SWC control and configuration registers are battery backed, powered by VPP. The

setup of the wake-up events, including programmable sequences, is retained throughout power failures (no VSB) as long as

the battery is connected. VPP is taken from VSB if VSB is greater than the minimum (Min) value defined in the Device Char-

acteristics chapter; otherwise, VBAT is used as the VPP source.

Hardware reset does not affect these registers. They are reset only by software reset or power-up of VPP.

3.3

EVENT DETECTION

3.3.1

Modem Ring

High to low transitions on RI1 or RI2 indicate the detection of ring in external modem connected to Serial Port 1 or Serial

Port 2, respectively, and can be used as wake-up events.

3.3.2

Telephone Ring

A telephone ring is detected by the SWC by processing the raw signal coming directly from the telephone line into the RING

input pin. Detection of a pulse-train with a frequency higher than 16 Hz that lasts at least 0.19 sec, is used as a wake-up

event.

The RING pulse-train detection is achieved by monitoring the falling edges on RING in time slots of 62.5 msec (a 16 Hz

cycle). A positive detection occurs if falling edges of RING are detected in three consecutive time slots, following a time slot

in which no RING falling edge is detected. This detection method guarantees the detection of a RING pulse-train with fre-

quencies higher than 16 Hz. It ﬁlters out (does not detect) pulses of less than 10 Hz, and may detect pulses between 10 Hz

to 16 Hz.

3.3.3

Keyboard and Mouse Activity

The detection of either any activity or a specific predetermined keyboard or mouse activity can be used as a wake-up event.

The keyboard wake-up detection can be programmed to detect:

Any keystroke

A speciﬁc programmable sequence of up to eight alphanumeric keystrokes

Any programmable sequence of up to 8 bytes of data received from the keyboard.

The mouse wake-up detection can be programmed to detect either any mouse click or movement, or a specific programma-

ble click (left or right) or double-clicks.

The keyboard or mouse event detection operates independently of the KBC (which is powered down with the rest of the system).

WK_X2ENn.i

WK_X1ENn.i

Wake-Up Filtered Event i

VDD Present

To Event i

Detection

Logic

Post VDD Power-On Silence

Post VSB Power-On Silence

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