DS2450 View Datasheet(PDF) - Maxim Integrated
Part Name
Description
Manufacturer
DS2450 Datasheet PDF : 25 Pages
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MEMORY MAP PAGE 2, ALARM SETTINGS Figure 5c
Address
10
11
12
13
14
15
16
17
bit 7
MSBL-A
MSBH-A
MSBL-B
MSBH-B
MSBL-C
MSBH-C
MSBL-D
MSBH-D
bit 6
A
A
B
B
C
C
D
D
bit 5
A
A
B
B
C
C
D
D
bit 4
A
A
B
B
C
C
D
D
bit 3
A
A
B
B
C
C
D
D
bit 2
A
A
B
B
C
C
D
D
bit 1
A
A
B
B
C
C
D
D
DS2450
bit 0
LSBL-A
LSBH-A
LSBL-B
LSBH-B
LSBL-C
LSBH-C
LSBL-D
LSBH-D
The registers for the alarm threshold voltages of each channel are located in memory page 2 with the low
threshold being at the lower address (Figure 5c). The power-on default thresholds are 00h for low alarm
and FFh for high alarm. The alarm settings are always eight bits. For a resolution higher or equal to
eight bits the alarm flag will be set if the eight most significant bits of the conversion result yield a
number higher than stored in the high alarm register (AFH) or lower than stored in the low alarm register
(AFL). For a resolution lower than eight bits the least significant bits of the alarm registers are ignored.
MEMORY MAP PAGE 3, Factory Calibration, VCC Control Byte Figure 5d
Address
18
Factory Calibration (do not change)
19
Factory Calibration (do not change)
1A
Factory Calibration (do not change)
1B
Factory Calibration (do not change)
1C
Set to 40 hex if VCC powered
1D
Factory Calibration (do not change)
1E
Factory Calibration (do not change)
1F
Factory Calibration (do not change)
There is a fourth memory page in the address range of 18 to 1F used during calibration at the factory.
This memory page is accessible to the user through the Read Memory and Write Memory commands.
Changing the data of this page arbitrarily will de-calibrate the A/D converter or make the device
nonfunctional until it undergoes a power-on reset. If the device is VCC powered the analog circuitry
must be kept permanently active by writing a value of 40 hex to memory address 1C after power-up.
This also eliminates the offset time otherwise needed with each CONVERT command. See the
description of the CONVERT command for details.
FUNCTION COMMANDS
The Function Command Flow Chart (Figure 6) describes the protocols necessary for accessing the device
registers. Since the memory map of the DS2450 is small compared to the 16-bit addressing capabilities
the 11 most significant bits of the address will be forced to 0 before they enter the CRC-generator. The
communication between master and DS2450 takes place either at regular speed (default, OD = 0) or at
Overdrive Speed (OD = 1). If not explicitly set into Overdrive mode the device assumes regular speed.
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