OM11014 NXP Semiconductors, OM11014 Datasheet - Page 41

• Manufacturer Part Number: OM11014
• Description: BOARD EVAL FOR LPC2919
• Manufacturer: NXP Semiconductors
• Series: Keilr
• Type: MCUr

Specifications of OM11014

• Contents: Board, Cable, CD
• For Use With/related Products: LPC2919
• Lead Free Status / RoHS Status: Not applicable / Not applicable
• Other names: 568-4360

NXP Semiconductors
LPC2917_19_1
Product data sheet
8.8.4.1 Overview
8.8.4.2 Description
8.8.3 PCR subsystem clock description
8.8.4 Clock Generation Unit (CGU)
The PCRSS is clocked by a number of different clocks. CLK_SYS_PCRSS clocks the
AHB side of the AHB to DTL bus bridge and CLK_PCR_SLOW clocks the CGU, RGU and
PMU internal logic, see
BASE_SYS_CLK, which can be switched off in low-power modes. CLK_PCR_SLOW is
derived from BASE_PCR_CLK and is always on in order to be able to wake up from
low-power modes.
The key features are:
Remark: Any clock-frequency adjustment has a direct impact on the timing of on-board
peripherals such as the UARTs, SPI, watchdog, timers, CAN controller, LIN master
controller, ADCs or flash memory interface.
The clock generation unit provides 10 internal clock sources as described in
Table 23.
[1]
[2]
Numbe
r
0
1
2
3
4
5
6
7
8
•
•
•
•
•
•
•
•
•
•
Generation of 10 and 2 test-base clocks, selectable from several embedded clock
sources
Crystal oscillator with power-down
Control PLL with power-down
Very low-power ring oscillator, always on to provide a ‘safe clock’
Seven fractional clock dividers with L/D division
Individual source selector for each base clock, with glitch-free switching
Autonomous clock-activity detection on every clock source
Protection against switching to invalid or inactive clock sources
Embedded frequency counter
Register write-protection mechanism to prevent unintentional alteration of clocks
Maximum frequency that guarantees stable operation of the LPC2917/19.
Fixed to low-power oscillator.
Name
BASE_SAFE_CLK
BASE_SYS_CLK
BASE_PCR_CLK
BASE_IVNSS_CLK
BASE_MSCSS_CLK
BASE_UART_CLK
BASE_SPI_CLK
BASE_TMR_CLK
BASE_ADC_CLK
CGU base clocks
Rev. 01 — 31 July 2008
Section
7.2.2. CLK_SYS_PCRSS is derived from
Frequency
(MHz)
0.4
80
0.4
80
80
80
40
80
4.5
[2]
[1]
ARM9 microcontroller with CAN and LIN
Description
base safe clock (always on)
base system clock
base PCR subsystem clock
base IVNSS subsystem clock
base MSCSS subsystem clock
base UART clock
base SPI clock
base timers clock
base ADCs clock
LPC2917/19
© NXP B.V. 2008. All rights reserved.
Table
23.
41 of 67