G768B View Datasheet(PDF) - Global Mixed-mode Technology Inc
Part Name
Description
Manufacturer
G768B
Global Mixed-mode Technology Inc
G768B Datasheet PDF : 15 Pages
| |||
Global Mixed-mode Technology Inc.
G768B
Write Byte Format
S
Address
WR
ACK Command ACK
DATA
ACK
P
7 bits
8 bits
8 bits
1
Slave Address: equivalent to chip-select line of a 3-wire interface
Command Byte: selects, which register you, are writing to
Data Byte: data goes into the register set by the command byte (to set thresholds, configuration masks, and
sampling rate)
Read Byte Format
S Address WR ACK Command ACK S Address RD ACK DATA /// P
7 bits
8 bits
7 bits
8 bits
Slave Address: equivalent to chip- select line
Command Byte: selects, which register you, are reading from
Slave Address: repeated due to change in data-flow direction
Data byte: reads from the register set by the command byte
Send Byte Format
S
Address
WR
ACK
Command
ACK
P
7 bits
8 bits
Command Byte: sends command with no data usually used for one-shot command
Receive Byte Format
S
Address
RD
ACK
Data
///
P
7 bits
8 bits
Data Byte: reads data from the register commanded by the last Read Byte or Write
Byte transmission; also used for SMBus Alert Response return address
S = Start condition Shaded = Slave transmission P = Stop condition /// = Not acknowledged
Fig 5. SMBus Protocols
Table 3. Data Format (Twos-Complement)
TEMP.
(°C)
ROUND
TEMP.
(°C)
DIGITAL OUTPUT
DATA BITS
SIGN
MSB LSB
+130.00
+127
0
111
1111
+127.00
+127
0
111
1111
+126.50
+127
0
111
1111
+126.00
+126
0
111
1110
+25.25
+25
0
001
1001
+0.50
+1
0
000
0001
+0.25
+0
0
000
0000
+0.00
+0
0
000
0000
-0.25
+0
0
000
0000
-0.50
+0
0
000
0000
-0.75
-1
1
111
1111
-1.00
-1
1
111
1111
-25.00
-25
1
110
0111
-25.50
-25
1
110
0110
-54.75
-55
1
100
1001
-55.00
-55
1
100
1001
-65.00
-65
1
011
1111
-70.00
-65
1
011
1111
Alarm Threshold Registers
Four registers store alarm threshold data, with
high-temperature (THIGH) and low-temperature
(TLOW) registers for each A/D channel. If either
measured temperature equals or exceeds the corre-
sponding alarm threshold value, an ALERT interrupt
is asserted.
The power-on-reset (POR) state of both THIGH regis-
ters is full scale (0111 1111, or +127°C). The POR
state of both TLOW registers is 1100 1001 or -55°C.
Diode Fault Alarm
There is a continuity fault detector at DXP that detects
whether the remote diode has an open-circuit condi-
tion. At the beginning of each conversion, the diode
fault is checked, and the status byte is updated. This
fault detector is a simple voltage detector; if DXP rises
above VCC - 1V (typical) due to the diode current
source, a fault is detected. Note that the diode fault
isn't checked until a conversion is initiated, so imme-
diately after power-on reset the status byte indicates
no fault is present, even if the diode path is broken.
Ver 1.3
Oct 28, 2002
TEL: 886-3-5788833
http://www.gmt.com.tw
10
Share Link: