pc87591l National Semiconductor Corporation, pc87591l Datasheet - Page 361

• Manufacturer Part Number: pc87591l
• Description: Lpc Mobile Embedded Controllers
• Manufacturer: National Semiconductor Corporation

Revision 1.07
Host-Controlled Modules and Host Interface
Figure 119 shows typical battery current consumption during battery-backed operation; Figure 120 shows typical battery
current consumption during normal operation.
6.2.10 System Bus Lockout
During power on or power off, spurious bus transactions from the host may occur. To protect the RTC internal registers from
corruption, all inputs are automatically locked out. The lockout condition is asserted when V
6.2.11 Power-Up Detection
When system power is restored after a power failure or power off state (V
of 62 ms (minimum) to 125 ms (maximum) after the RTC switches from battery to system power.
The lockout condition is switched off immediately in the following situations:
If the Divider Chain Control bits, DV0-2, (bits 6-4 in CRA register) specify a normal operation mode (010
signals are enabled immediately on detection of system voltage above V
When battery voltage is below V
mediately on detection of system voltage above V
If bit 7 (VRT) of CRD register is 0, all input signals are enabled immediately on detection of system voltage above V
3.3V - 3.6V
V
V
PP2CC
CC2PP
V
V
BAT
PP
Figure 119. Typical Battery Current During Battery-Backed Power Mode
Figure 120. Typical Battery Current During Normal Operation Mode
V
Note: Battery voltage in this test is 3.0V.
V
CC
PP
uses V
Figure 118. V
BATDCT
BAT
and host domain hardware reset is active, all input signals are enabled im-
I
I
BAT
BAT
PP
0.20
0.15
0.10
0.05
1.0
0.9
0.8
0.7
( A)
( A)
CCON
Generation Using V
V
PP
V
361
. This also initializes registers at offsets 00
uses V
BAT
2.4 3.0 3.6
3.0 3.3 3.6
(Continued)
CC
CC
=0), the lockout condition continues for a delay
V
CC
BAT (V)
CCON
V
or V
PP
V
V
CC
.
uses V
CC
BAT
(V)
BAT
CC
V
PP
is lower than V
time
16
through 0D
CCON
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2
), all input
.
CCON
16
.
.