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UM10237_2
© NXP B.V. 2008. All rights reserved.
User manual
Rev. 02 — 19 December 2008
58 of 792
NXP Semiconductors
UM10237
Chapter 4: LPC24XX Clocking and power control
3.3.4 Peripheral Clock Selection registers 0 and 1 (PCLKSEL0 - 0xE01F C1A8 and
PCLKSEL1 - 0xE01F C1AC)
A pair of bits in a Peripheral Clock Selection register controls the rate of the clock signal
that will be supplied to the corresponding peripheral as specified in
and
[1]
For PCLK_RTC only, the value ’01’ is illegal. Do not write ’01’ to the PCLK_RTC. Attempting to write ’01’
results in the previous value being unchanged.
Table 55.
IRC Trim register (IRCTRIM - address 0xE01F C1A4) bit description
Bit
Symbol
Description
Reset
value
7:0
IRCtrim
IRC trim value. It controls the on-chip 4 MHz IRC frequency.
0xA0
15:8
-
Reserved. Software must write 0 into these bits.
NA
Table 56.
Peripheral Clock Selection register 0 (PCLKSEL0 - address 0xE01F C1A8) bit
description
Bit
Symbol
Description
Reset
value
1:0
PCLK_WDT
Peripheral clock selection for WDT.
00
3:2
PCLK_TIMER0
Peripheral clock selection for TIMER0.
00
5:4
PCLK_TIMER1
Peripheral clock selection for TIMER1.
00
7:6
PCLK_UART0
Peripheral clock selection for UART0.
00
9:8
PCLK_UART1
Peripheral clock selection for UART1.
00
11:10
PCLK_PWM0
Peripheral clock selection for PWM0.
00
13:12
PCLK_PWM1
Peripheral clock selection for PWM1.
00
15:14
PCLK_I2C0
Peripheral clock selection for I2C0.
00
17:16
PCLK_SPI
Peripheral clock selection for SPI.
00
19:18
PCLK_RTC
Peripheral clock selection for RTC.
00
21:20
PCLK_SSP1
Peripheral clock selection for SSP1.
00
23:22
PCLK_DAC
Peripheral clock selection for DAC.
00
25:24
PCLK_ADC
Peripheral clock selection for ADC.
00
27:26
PCLK_CAN1
Peripheral clock selection for CAN1.
00
29:28
PCLK_CAN2
Peripheral clock selection for CAN2.
00
31:30
PCLK_ACF
Peripheral clock selection for CAN filtering.
00
Table 57.
Peripheral Clock Selection register 1 (PCLKSEL1 - address 0xE01F C1AC) bit
description
Bit
Symbol
Description
Reset
value
1:0
PCLK_BAT_RAM
Peripheral clock selection for the battery supported RAM.
00
3:2
PCLK_GPIO
Peripheral clock selection for GPIOs.
00
5:4
PCLK_PCB
Peripheral clock selection for the Pin Connect block.
00
7:6
PCLK_I2C1
Peripheral clock selection for I2C1.
00
9:8
-
Unused, always read as 0.
00
11:10
PCLK_SSP0
Peripheral clock selection for SSP0.
00