OM11077 NXP Semiconductors, OM11077 Datasheet - Page 586

• Manufacturer Part Number: OM11077
• Description: MODULE DIMM LPC2478 ARM7
• Manufacturer: NXP Semiconductors

Specifications of OM11077

• Accessory Type: Module Card
• For Use With/related Products: ARM-57TS-LPC2478
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 568-4742

NXP Semiconductors
9. Details of I
UM10237_4
User manual
2
The values for I2SCLL and I2SCLH should not necessarily be the same. Software can set
different duty cycles on SCL by setting these two registers. For example, the I
specification defines the SCL low time and high time at different values for a 400 kHz I
rate. The value of the register must ensure that the data rate is in the I
of 0 through 400 kHz. Each register value must be greater than or equal to 4.
Table 22–520
I2SCLL and I2SCLH values.
Table 520. Example I
The four operating modes are:
Data transfers in each mode of operation are shown in Figures
lists abbreviations used in these figures when describing the I
Table 521. Abbreviations used to describe an I
C operating modes
I2SCLL +
I2SCLH
8
10
25
50
100
160
200
400
800
Abbreviation
S
SLA
R
W
A
•
•
•
•
Master Transmitter
Master Receiver
Slave Receiver
Slave Transmitter
1
125
100
40
20
10
6.25
5
2.5
1.25
gives some examples of I
2
C Clock Rates
Rev. 04 — 26 August 2009
Explanation
Start Condition
7 bit slave address
Read bit (high level at SDA)
Write bit (low level at SDA)
Acknowledge bit (low level at SDA)
5
200
100
50
31.25
25
12.5
6.25
I 2 C
bitfrequency
I
2
C Bit Frequency (kHz) at PCLK (MHz)
10
400
200
100
62.5
50
25
12.5
2
=
C bus rates based on PCLK frequency and
Chapter 22: LPC24XX I
-------------------------------------------------------- -
I2CSCLH
16
320
160
100
80
40
20
2
C operation
f
PCLK
+
I2CSCLL
20
400
200
100
25
125
50
2
C operating modes.
120
2
40
400
250
200
100
50
C interfaces I
to 124.
UM10237
2
© NXP B.V. 2009. All rights reserved.
C data rate range
Table 22–521
2
C bus
60
375
300
150
75
586 of 792
2
C0/1/2
(12)
2
C