3-26
Intel® PXA255 Processor
Developer’s Manual
Clocks and Power Manager
3.5.4
Power Manager Rising-Edge Detect Enable Register (PRER)
The PRER, shown in
Table 3-10
, determines whether the GPIO pin enabled with the PWER
register causes a wake up from sleep mode on that GPIO pin’s rising edge. When PWER[IDAE] is
zero and a fault condition is detected on the nVDD_FAULT or nBATT_FAULT pin, PRER is set to
0x0000_0003. This enables rising edges on GP[1:0] to act as wake up sources. When
PWER[IDAE] is set, fault conditions on the nVDD_FAULT or nBATT_FAULT pins do not affect
wake-up sources. PRER is also set to 0x0000_0003 in hardware, watchdog, and GPIO resets.
Software should enable wakeups only for those GPIO pins that are configured as inputs during
sleep. Any GPIO pins that are configured as outputs during sleep, should have their associated
wake enable bits set to logic zero in all three PMU wake enable registers (PWER, PRER, and
PFER).
This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.
Table 3-10. PRER Bit Definitions
0x40F0_0010
PRER
Clocks and Power Manager
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Re
se
rv
e
d
RE
1
5
RE
1
4
RE
1
3
RE
1
2
RE1
1
RE
1
0
RE
9
RE
8
RE
7
RE
6
RE
5
RE
4
RE
3
RE
2
RE
1
RE
0
Reset
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1
Bits
Name
Description
[31:16]
—
Reserved.
Read undefined and must always be written with zeroes.
[15:0]
REx
Sleep mode Rising-edge Wake up Enable
0 – Wake up due to GPx rising-edge detect disabled.
1 – Wake up due to GPx rising-edge detect enabled.
Set to 0x 0003 on hardware, watchdog, and GPIO resets.
Summary of Contents for PXA255
Page 1: ...Intel PXA255 Processor Developer s Manual January 2004 Order Number 278693 002 ...
Page 24: ...xxiv Intel PXA255 Processor Developer s Manual Contents ...
Page 30: ...1 6 Intel PXA255 Processor Developer s Manual Introduction ...
Page 310: ...7 46 Intel PXA255 Processor Developer s Manual LCD Controller ...
Page 330: ...8 20 Intel PXA255 Processor Developer s Manual Synchronous Serial Port Controller ...
Page 358: ...9 28 Intel PXA255 Processor Developer s Manual I2 C Bus Interface Unit ...
Page 488: ...13 36 Intel PXA255 Processor Developer s Manual AC 97 Controller Unit ...
Page 572: ...16 30 Intel PXA255 Processor Developer s Manual Network SSP Serial Port ...
Page 599: ...Intel PXA255 Processor Developer s Manual 17 27 Hardware UART ...
Page 600: ......