Actel Fusion Mixed-Signal FPGAs
The fourth section of the Analog Quad is called the Temperature Monitor Block, and its input pin
name is AT. This block is similar to the Voltage Monitor Block, except that it has an additional
function: it can be used to monitor the temperature of an external diode-connected transistor. It
has a modified prescaler and is limited to positive voltages only.
The Analog Quad can be configured during design time by Actel Libero IDE; however, the ACM can
be used to change the parameters of any of these I/Os during runtime. This type of change is
referred to as a context switch. The Analog Quad is a modular structure that is replicated to
generate the analog I/O resources. Each Fusion device supports between 5 and 10 Analog Quads.
The analog pads are numbered to clearly identify both the type of pad (voltage, current, gate
driver, or temperature pad) and its corresponding Analog Quad (AV0, AC0, AG0, AT0, AV1, …, AC9,
AG9, and AT9). There are three types of input pads (AVx, ACx, and ATx) and one type of analog
output pad (AGx). Since there can be up to 10 Analog Quads on a device, there can be a maximum
of 30 analog input pads and 10 analog output pads.
Off-Chip
AV
AC
AG
AT
Voltage
Monitor Block
Current
Monitor Block
Gate
Driver
Temperature
Monitor Block
Pads
On-Chip
Analog Quad
Prescaler
Prescaler
Prescaler
Power
MOSFET
Gate Driver
Digital
Input
Digital
Input
Digital
Input
Current
Monitor/Instr
Amplifier
Temperature
Monitor
To FPGA
(DAVOUTx)
To FPGA
(DACOUTx)
From FPGA
(GDONx)
To FPGA
(DATOUTx)
To Analog MUX
To Analog MUX
To Analog MUX
Figure 2-65 • Analog Quad
Preliminary v1.7
2-85
ACTEL [ Actel Corporation ]
