© Koninklijke Philips Electronics N.V. 2005. All rights reserved.
User manual
Rev. 01 — 15 August 2005
37
Philips Semiconductors
UM10139
Volume 1
Chapter 3: System Control Block
additional circuitry to reduce power. Each bit in PCONP controls one of the peripherals.
The bit numbers correspond to the related peripheral number as shown in the VPB
peripheral map
Table 2 “VPB peripheries and base addresses”
in the "LPC2141/2/4/6/8
Memory Addressing" chapter.
If a peripheral control bit is 1, that peripheral is enabled. If a peripheral bit is 0, that
peripheral is disabled to conserve power. For example if bit 19 is 1, the I
2
C1 interface is
enabled. If bit 19 is 0, the I
2
C1 interface is disabled.
Important: valid read from a peripheral register and valid write to a peripheral
register is possible only if that peripheral is enabled in the PCONP register!
Table 26:
Power Control for Peripherals register (PCONP - address 0xE01F C0C4) bit
description
Bit
Symbol
Description
Reset
value
0
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
NA
1
PCTIM0
Timer/Counter 0 power/clock control bit.
1
2
PCTIM1
Timer/Counter 1 power/clock control bit.
1
3
PCUART0 UART0 power/clock control bit.
1
4
PCUART1 UART1 power/clock control bit.
1
5
PCPWM0
PWM0 power/clock control bit.
1
6
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
NA
7
PCI2C0
The I
2
C0 interface power/clock control bit.
1
8
PCSPI0
The SPI0 interface power/clock control bit.
1
9
PCRTC
The RTC power/clock control bit.
1
10
PCSPI1
The SSP interface power/clock control bit.
1
11
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
NA
12
PCAD0
A/D converter 0 (ADC0) power/clock control bit.
Note: Clear the PDN bit in the AD0CR before clearing this bit, and set
this bit before setting PDN.
1
18:13
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
NA
19
PCI2C1
The I
2
C1 interface power/clock control bit.
1
20
PCAD1
A/D converter 1 (ADC1) power/clock control bit.
Note: Clear the PDN bit in the AD1CR before clearing this bit, and set
this bit before setting PDN.
1
30:21
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
NA
31
PUSB
USB power/clock control bit.
0