PC87366 datasheet(84/240 Pages) NSC

84 / 240 page

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

www.national.com

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).

3.3.4

CEIR Address

A CEIR transmission received on an IRRX pin in a pre-selected standard (NEC, RCA or RC-5) is matched against a pro-

grammable CEIR address. Detection of matching can be used as a wake-up event.

Whenever an IR signal is detected, the receiver immediately enters the active state. When this happens, the receiver keeps

sampling the IR input signal and generates a bit string where a logic 1 indicates an idle condition and a logic 0 indicates the

presence of IR energy. The received bit string is de-serialized and assembled into 8-bit characters.

The expected CEIR protocol of the received signal should be configured through bits 5,4 at the CEIR Wake-Up Control reg-

ister (see Section 3.4.22).

The CEIR Wake-Up Address register (IRWAD) holds the unique address to be compared with the address contained in the

incoming CEIR message. If CEIR is enabled (bit 0 of the IRWCR register is 1) and an address match occurs, then the CEIR

Event Status bit of the WK_STS0 register is set to 1 (see Section 3.4.2).

The CEIR Address Shift register holds the received address which is compared with the address contained in the IRWAD.

The comparison is affected also by the CEIR Wake-Up Address Mask register (IRWAM) in which each bit determines wheth-

er to ignore the corresponding bit in the IRWAD.

If CEIR routing to interrupt request is enabled, the assigned SWC interrupt request may be used to indicate that a complete

address has been received. To get this interrupt when the address is completely received, the IRWAM should be written with

FFh. Once the interrupt is received, the value of the address can be read from the ADSR register.

Another parameter that is used to determine whether a CEIR signal is to be considered valid is the bit cell time width. There

are four time ranges for the different protocols and carrier frequencies. Four pairs of registers define the low and high limits

of each time range. (See Sections 3.4.29 through for more details regarding the recommended values for each protocol.)

The CEIR address detection operates independently of the serial port with the IR (which is powered down with the rest of

the system).

3.3.5

Standby General-Purpose Input Events

A general-purpose event is defined as the detection of falling edge, rising edge, low level or high level on a specific signal.

Each signal’s event is configurable via software. GPIOE0-5 and GPIE6-7 may trigger a system notification by any of the

means mentioned in Section 3.1.

A debouncer of 16 ms is enabled (default) on each event. It may be disabled by software.

3.3.6

GPIO-Triggered Events

A GPIO-triggered event is defined as the detection of falling edge, rising edge, low level or high level on a specific GPIO

signal whose status bit is routed to PWUREQ. Each signal’s event is configurable via software in the GPIO logical device

configuration registers. GPIO00-07, GPIO10-14, GPIO16-17 may trigger a system notification only by PWUREQ. Other

means of system notiﬁcation triggered by GPIOs are available via the GPIO logical device conﬁguration registers.

A debouncer of 16 ms is enabled (default) on each event. It may be disabled by software.

All GPIO pins are powered by VDD, and therefore can cause an assertion of PWUREQ only when VDD is present.

3.3.7

Software Event

A software event is defined as writing 1 to the Software Event Status bit of the WK_STS0 register. Once this bit is set to 1,

it has the same effect as any other Event Status bit.

Since WK_STS0 is accessible only when VDD is present, the Software Event can be activated only when VDD is present.

PC87366 Datasheet(PDF) 84 Page - National Semiconductor (TI)

PC87366 Datasheet(HTML) 84 Page - National Semiconductor (TI)

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