dimtel
dimtel
9.3
Environmental monitor
Table 11: Drive pattern memory
Address
Bits
Definition
0x040000-0x45fff
8:0
Drive pattern memory, even samples
0x040000-0x45fff
20:12
Drive pattern memory, odd samples
0x048000-0x487ff
3:0
Bunch mask memory, bit 0 - first
bunch, bit 1 - last
9.3
Environmental monitor
iGp-5120F uses two MAX1299 devices for monitoring five temperatures and
three power supply voltages. The SPI interface module for the controller
uses sixteen addresses, as described in table 12.
Let’s consider the first device (addresses
0x110
–
0x117
). Analog inputs 0
and 1 (AIN0, AIN1) are connected to the FPGA temperature diode. General
conversion function from the raw register value to temperature in degrees
Celsius is
x/
32
−
273
.
15. Analog inputs 2 and 3 are used to measure the
temperature of the MAX104 ADC. The ADC provides two current sources
I
ptat
and
I
pconst
for temperature measurement. ADC temperature is given by
300
I
ptat
/I
pconst
−
273. In the iGp-5120F the two sources are loaded by 5.1 kΩ
resistors and connected to AIN2 and AIN3.
MAX1299 also measures the ambient chassis temperature via the internal
diode. Two supply voltages are measured: FPGA core (1.5 V) connected to
AIN4 and 3.3 V supply internally measured by MAX1299. Raw register value
can be converted to voltage by 2
.
4
×
X/
16384. For the 3.3 V supply the value
must be multiplied by 4, since MAX1299 monitors
V
dd
/
4.
The second device is configured for external temperature sensors at AIN0–
AIN1 and AIN2–AIN3. AIN4 is connected to a resistive divider monitoring
bulk 12 V supply. Divider ratio is 1
/
6 for 2 V nominal ADC input.
Table 12: FPGA registers: MAX1299 monitors
Address
Bits
Definition
0x000110
15:0
Device 1, AIN2 (
V
ptat
)
0x000111
15:0
Device 1, AIN3 (
V
pconst
)
0x000112
15:0
Device 1, AIN4, FPGA core voltage
V
int
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