M1AFS250-FGG256I Actel Corporation, M1AFS250-FGG256I Datasheet - Page 100

• Manufacturer Part Number: M1AFS250-FGG256I
• Description: Actel Fusion Family Of Mixed Signal Fpgas
• Manufacturer: Actel Corporation

Device Architecture
Table 2-36 • Analog Block Pin Description (continued)
2- 84
Signal Name
AG6
AT6
ATRETURN67
AV7
AC7
AG7
AT7
AV8
AC8
AG8
AT8
ATRETURN89
AV9
AC9
AG9
AT9
RTCMATCH
RTCPSMMATCH
RTCXTLMODE[1:0]
RTCXTLSEL
RTCCLK
Analog Quad
With the Fusion family, Actel introduces the Analog Quad, shown in
basic analog I/O structure. The Analog Quad is a four-channel system used to precondition a set of
analog signals before sending it to the ADC for conversion into a digital signal. To maximize the
usefulness of the Analog Quad, the analog input signals can also be configured as LVTTL digital input
signals. The Analog Quad is divided into four sections.
The first section is called the Voltage Monitor Block, and its input pin is named AV. It contains a two-
channel analog multiplexer that allows an incoming analog signal to be routed directly to the ADC or
allows the signal to be routed to a prescaler circuit before being sent to the ADC. The prescaler can be
configured to accept analog signals between –12 V and 0 or between 0 and +12 V. The prescaler circuit
scales the voltage applied to the ADC input pad such that it is compatible with the ADC input voltage
range. The AV pin can also be used as a digital input pin.
The second section of the Analog Quad is called the Current Monitor Block. Its input pin is named AC.
The Current Monitor Block contains all the same functions as the Voltage Monitor Block with one
addition, which is a current monitoring function. A small external current sensing resistor (typically less
than 1 Ω) is connected between the AV and AC pins and is in series with a power source. The Current
Monitor Block contains a current monitor circuit that converts the current through the external resistor to
a voltage that can then be read using the ADC.
Number
of Bits
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
2
1
1
Direction
Output
Output
Output
Output
Output
Output
Output
Output
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
Input
R e visio n 1
Temperature monitor return shared by
Analog Quads 6 and 7
Analog Quad 7
Analog Quad 8
Temperature monitor return shared by
Analog Quads 8 and 9
Analog Quad 9
MATCH
MATCH connected to VRPSM
Drives XTLOSC RTCMODE[1:0] pins
Drives XTLOSC MODESEL pin
RTC clock input
Function
Figure 2-66 on page
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Analog Quad
Location of
2-85, as the
Details
RTC
RTC
RTC
RTC
RTC