SS8018TR SSC [Silicon Standard Corp.], SS8018TR Datasheet - Page 11

• Manufacturer Part Number: SS8018TR
• Manufacturer: SSC [Silicon Standard Corp.]

Rev.2.01 6/06/2003
Table 6. Configuration-Byte Bit Assignments
Table 7. Status-Byte Bit Assignments
*These flags stay high until cleared by POR, or until the status byte register is read.
Table 8. Conversion-Rate Control Byte
To check for internal bus collisions, read the status byte.
If the least significant seven bits are ones, discard the
data and read the status byte again. The status bits
LHIGH, LLOW, RHIGH, and RLOW are refreshed on the
SMBus clock edge immediately following the stop condi-
tion, so there is no danger of losing temperature-related
status data as a result of an internal bus collision. The
OPEN status bit (diode continuity fault) is only refreshed
at the beginning of a conversion, so OPEN data is lost.
The
byte register, so no false alerts are generated by an in-
ternal bus collision.
7 (MSB)
09h to FFh
7 (MSB)
BIT
0 (LSB)
5-0
6
DATA
ALERT
BIT
00h
01h
02h
03h
04h
05h
06h
07h
08h
6
5
4
3
2
1
NAME
interrupt latch is independent of the status
MASK
STOP
RUN
RFU
/
RHIGH*
RTHRM
LHIGH*
RLOW*
LTHRM
NAME
LLOW*
OPEN*
CONVERSION RATE (Hz)
BUSY
POR STATE
0
0
0
0.0625
0.125
RFU
0.25
A high indicates that the ADC is busy converting.
A high indicates that the local high-temperature alarm has activated.
A high indicates that the local low-temperature alarm has activated.
A high indicates that the remote high-temperature alarm has activated.
A high indicates that the remote low-temperature alarm has activated.
A high indicates a remote-diode continuity (open-circuit) fault.
A high indicates a remote temperature
A high indicates a local temperature
0.5
16
1
2
4
8
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Masks all
Standby mode control bit. If high, the device immediately stops converting and en-
ters standby mode. If low, the device converts in either one-shot or timer mode.
Reserved for future use
ALERT
interrupts when high.
When auto-converting, if the THIGH and TLOW limits
are close together, it’s possible for both high-temp and
low-temp status bits to be set, depending on the amount
of time between status read operations (especially when
converting at the fastest rate). In these circumstances,
it’s best not to rely on the status bits to indicate reversals
in long-term temperature changes and instead use a
current temperature reading to establish the trend direc-
tion.
For bit 1 and bit 0, a high indicates a temperature alarm
happened for remote and local diode respectively. The
cleared when reading status byte.
Conversion Rate Byte
The conversion rate register (Table 8) programs the time
interval
auto-convert mode. This variable rate control reduces
the supply current in portable-equipment applications.
The conversion rate byte’s POR state is 08h (16Hz).
The SS8018 looks only at the 4 LSB bits of this register,
so the upper 4 bits are “don’t care” bits, which should be
set to zero. The conversion rate tolerance is 25% at
any rate setting.
Valid A/D conversion results for both channels are
available one total conversion time (125ms,typical) after
initiating a conversion, whether conversion is initiated
via the
power-up.
THERM
THERM
THERM
FUNCTION
pin also asserts. These two bits wouldn’t be
FUNCTION
RUN
alarm has activated.
between
alarm has activated.
/STOP bit, one-shot command, or initial
conversions
in
free-running
SS8018
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