MAX6621AUB+ MAXIM [Maxim Integrated Products], MAX6621AUB+ Datasheet - Page 8

• Manufacturer Part Number: MAX6621AUB+
• Description: PECI-to-I2C Translator
• Manufacturer: MAXIM [Maxim Integrated Products]

Table 5. CONFIG2 Register
Table 6. Example Offset Values in 16-Bit
Temperature Representation
Table 7. CONFIG3 Register
PECI-to-I
The CONFIG2 register holds the offset that is added to
all temperature return values that are not error codes.
The offset is enabled in CONFIG0, bit 6; +95°C is set
as 17C0h or 005Fh, depending on the data format. To
represent +95°C in 16-bit representation, convert
+95°C to binary using two’s complement and left-shift
six times. The MAX6621 automatically converts the off-
set value to the equivalent value when the data format
is changed. See Table 5 for the default offset and Table
6 for some example values.
When configured in CONFIG2, and the return code is not
an error code (see the Error Codes section), the device
adds the offset value stored in CONFIG2 to the return
value. For example, if the CPU’s thermal control circuit
activation point is at +95°C, CONFIG2 can be set to
+95°C (005Fh or 17C0h) and all return values are con-
verted to absolute temperatures. Note that the thermal
control circuit activation point is CPU specific. The offset
value is represented in the current data format.
CONFIG3 register configures the temperature averaging
function. See the Temperature Averaging section for
more information. Table 7 shows the default settings.
8
BIT(S)
TEMP (°C)
BIT(S)
15:0
15:8
7:0
_______________________________________________________________________________________
+25
+50
+75
+95
0
Temperature offset
Reserved, set to 0
Averaging shift count, see formula
0C80h
12C0h
17C0h
0000h
0640h
HEX
DESCRIPTION
DESCRIPTION
2
C Translator
0000 0000
0000 0110
0000 1100
0001 0010
0001 0111
RESHI
BINARY
0000 0000
0100 0000
1000 0000
1100 0000
1100 0000
DEFAULT
RESLO
CONFIG2
CONFIG3
DEFAULT
0000h
00h
00h
Table 8. Example 16-Bit Representation
with No Offset (Activation Point = +95°C)
Temperature data is formatted in 16-bit two’s comple-
ment representing a range from -512°C to +512°C in
steps of 1/64°C (Figure 1). Internally, the device always
uses the 16-bit data format. The temperature is given in
two’s complement and left-shifted so that the +1°C bit
is bit 6 (Figure 2). Temperatures can be represented
externally in alternate data format if fractional readings
are not needed. Table 8 shows some examples.
Figure 1. Temperature Measured in 1/64°C Steps
Figure 2. Conversion of Temperature Done in Two’s
Complement
TEMP
RESHI
-50°C
15
(°C)
+94
+85
+70
+45
+20
14
RESLO
7
13
COMPLEMENT
RELATIVE
TEMP (°C)
12
TWO'S
1°C
6
-10
-25
-50
-75
11
-1
10
Temperature Representation
1
2
5
°C
9
4
FDC0h
ED30h
1
4
FFC0h
FD80h
8
F380h
HEX
1
°C
1
1
8
3
0
RESLO
7
°C
0
1111 1111
1111 1101
1111 1101
1111 0011
1110 1101
6
16
1
2
RESHI
1
°C
5
1
1
32
1
4
1
BINARY
0
°C
3
64
0
1
1100 0000
1000 0000
1100 0000
1000 0000
0100 0000
2
RESLO
°C
1
0