PC87591L datasheet(62/437 Pages) NSC

62 / 437 page

www.national.com

Revision 1.07

3.0

Power, Reset and Clocks

3.1

POWER

3.1.1

Power Planes

The PC87591x has four power planes (wells), as shown in Table 10.

Table 10. PC87591x Power Planes

For correct PC87591x operation, VCC must be applied whenever VDD is applied. Apply AVCC at the same time that VCC is

applied, protection is provided against rise-time differences only.

3.1.2

Power States

The PC87591x has three main power states:

●

Battery Fail

Host Domain, Suspend, Analog and Battery Backed power planes are all powered off (i.e., in this case VDD,VCC,

AVCC and VBAT are all inactive).

●

Power Fail

Host Domain, Suspend and Analog power planes are powered off. Battery Backed power plane is powered on (i.e.,

in this case VDD,VCC and AVCC are inactive; VBAT is active).

●

Power Applied

Suspend, Analog and Battery Backed power planes are powered on, Host Domain power plane may be on or off (i.e.,

in this case VCC,AVCC are active, VBAT and VDD may be active or inactive).

The Power Applied state has several sub-states, depending on the domain:

— The host domain has Host Power On and Host Power Off states, according to the VDD status;

— The core domain and host-core interface have Active and Idle states. For details, see Section 4.17 on page 235.

The following power states are illegal:

●

Host domain on and Suspend and/or Analog off (i.e., VDD active and VCC and/or AVCC are inactive).

●

Suspend on and Analog off (i.e., VCC active and AVCC inactive) and vice-versa.

Power Plane

Description

Power Pins Ground Pins

Host Domain

Powers the LPC interface and host controlled

functions (except for RTC and MSWC) and

some external signals1

1. See the tables in Section 2.2.1 on page 42 to Section 2.2.13, speciﬁcally the Power Well

column, for how the PC87591x external interface signals are assigned to various power

planes.

VDD

GND

Suspend

Powers the core domain, the host-core interface,

the MSWC and their external signals1

VCC

GND

Analog

Powers some internal analog circuits and their

external signals1

AVCC

AGND

Battery Backed

Powers the RTC, some MSWC registers, the

32.768 KHz clock/crystal oscillator signals and

some other storage elements that should be

preserved at all times1

VPP

2. VPP is an internal power signal derived from VCC or VBAT. VPP is taken from VCC if it is

greater than the minimum value defined; otherwise, VBAT is used as the VPP source. For

more details on the switching between them, refer to Section 6.2.9 on page 360.

GND

PC87591L Datasheet(PDF) 62 Page - National Semiconductor (TI)

PC87591L Datasheet(HTML) 62 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