afs600 Actel Corporation, afs600 Datasheet - Page 101

• Manufacturer Part Number: afs600
• Description: Actel Fusion Programmable System Chips Mixed-signal Family With Optional Arm Support
• Manufacturer: Actel Corporation

Fusion uses a remote diode as a temperature sensor. The Fusion Temperature Monitor uses a differential input; the AT
pin and ATRTN (AT Return) pin are the differential inputs to the Temperature Monitor. There is one Temperature
Monitor in each Quad. A simplified block diagram is shown in
Figure 2-77 • Block Diagram for Temperature Monitor Circuit
The Fusion approach to measuring temperature is forcing two different currents through the diode with a ratio of
10:1. The switch that controls the different currents is controlled by the Temperature Monitor Strobe signal, TMSTB.
Setting TMSTB to '1' will initiate a Temperature reading. The TMSTB should remain '1' until the ADC finishes sampling
the voltage from the Temperature Monitor. The minimum sample time for the Temperature Monitor cannot be less
than the minimum strobe high time minus the setup time.
Figure 2-78 • Timing Diagram for the Temperature Monitor Strobe Signal
ADCSTART
10
TMSTBx
ATx
ATRTNxy
µA
V
ADC
TMSTBx
t
100
TMSLO
µA
∆V
–
+
t
A d v an c ed v1 . 4
VDD33A
TMSSET
+
–
12.5 X
Figure 2-78
Figure
t
TMSHI
ADC should start
sampling at this point
2-77.
shows the timing diagram.
Actel Fusion Programmable System Chips
V
ADC
for MUX Channel
(refer Table 2-36
to Analog MUX
Number)
2-87