pca2125 NXP Semiconductors, pca2125 Datasheet - Page 28

• Manufacturer Part Number: pca2125
• Description: Spi Real Time Clock / Calendar Semiconductors
• Manufacturer: NXP Semiconductors

NXP Semiconductors
PCA2125_00
Preliminary data sheet
Fig 19. Serial bus write example
Fig 20. Serial bus read example
address
address
counter
counter
SDO
SCL
SCL
SDI
SDI
CE
CE
R/W
R/W
b7
b7
xx
xx
0
1
b6
b6
0
0
b5
b5
0
In the following example, the months and years registers are read (see
example, SDI and SDO are not connected together. In this configuration, it is important
that SDI is never left floating, it must always be driven either high or low. If SDI is left open,
high I
0
b4
b4
1
1
DD
b3
b3
0
0
currents may result.
addr 02
addr 07
b2
b2
0
1
b1
b1
HEX
1
HEX
1
b0
b0
0
1
Rev. 00.11 — 30 January 2007
b7
b7
0
0
02
07
b6
b6
1
0
seconds data 45
months data 11
b5
b5
0
0
b4
b4
0
1
b3
b3
0
0
BCD
BCD
b2
b2
1
0
b1
b1
0
0
b0
b0
1
1
b7
b7
0
0
03
08
b6
b6
0
0
minutes data 10
SPI Real time clock / calendar
b5
b5
years data 06
0
0
b4
b4
1
0
b3
b3
0
0
BCD
BCD
b2
b2
0
1
PCA2125
© NXP B.V. 2007. All rights reserved.
Figure
b1
b1
0
1
001aaf915
001aaf916
b0
b0
0
0
20). In this
04
09
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