LPC2917 datasheet(36/68 Pages) PHILIPS

36 / 68 page

LPC2917_19_1

Preliminary data sheet

Rev. 1.01 — 15 November 2007

36 of 68

NXP Semiconductors

LPC2917/19

ARM9 microcontroller with CAN and LIN

The ADC clock is limited to 4.5 MHz maximum frequency and should always be lower

than or equal to the system clock frequency. To meet this constraint or to select the

desired lower sampling frequency the clock generation unit provides a programmable

fractional system-clock divider dedicated to the ADC clock. Conversion rate is determined

by the ADC clock frequency divided by the number of resolution bits plus one. Accessing

ADC registers requires an enabled ADC clock, which is controllable via the clock

generation unit, see Section 8.8.4.

Each ADC has four start inputs. Note that start 0 and start 2 are captured in the system

clock domain while start 1 and start 3 are captured in the ADC domain. The start inputs

are connected at MSCSS level, see Section 8.7.2.1 for details.

8.7.5.3

ADC pin description

The two ADC modules in the MSCSS have the pins described below. The ADCx input

pins are combined with other functions on the port pins of the LPC2917/19. The VREFN

and VREFP pins are common for both ADCs. Table 20 shows the ADC pins.

Fig 9.

ADC block diagram

ADC

control

registers

ADC

control

registers

VPB

system

bus

update

Conversion data

Config data

IRQ

Start 0

Start 2

Start 1

Start 3

CLK_ADCx_VPB

(MSCSS SubSystem clock)

CLK_ADCx

(ADC clock)

(upto 4.5 MHz)

Analog

inputs

ADC1: 8

ADC2: 8

Sync_out

ADC

IRQ

3.3 V

Analog

Digital

convertor

Analog

mux

ADC domain

VPB SubSystem

domain

001aad331 **

Table 20.

Analog to digital converter pins

Symbol

Direction

Description

ADCn IN[7:0]

analog input for ADCn, channel 7 to channel 0 (n is 1 or 2)

ADCn_EXT_START

ADC external start-trigger input (n is 1 or 2)

VREFN

ADC LOW reference level

VREFP

ADC HIGH reference level

LPC2917 数据表(PDF) 36 Page - NXP Semiconductors

LPC2917 数据表(HTML) 36 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68

数据表下载

链接网址

LPC2917 数据表(PDF) 36 Page - NXP Semiconductors

LPC2917 数据表(HTML) 36 Page - NXP Semiconductors

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68

数据表 下载

链接网址

数据表下载