M1AFS600-PQ208 Datasheet, PDF (246/334 Pages) Microsemi Corporation – Fusion Family of Mixed Signal FPGAs

Device Architecture
TMS
Test Mode Select
The TMS pin controls the use of the IEEE1532 boundary scan pins (TCK, TDI, TDO, TRST). There is an
internal weak pull-up resistor on the TMS pin.
TRST
Boundary Scan Reset Pin
The TRST pin functions as an active low input to asynchronously initialize (or reset) the boundary scan
circuitry. There is an internal weak pull-up resistor on the TRST pin. If JTAG is not used, an external pull-
down resistor could be included to ensure the TAP is held in reset mode. The resistor values must be
chosen from Table 2-183 and must satisfy the parallel resistance value requirement. The values in
Table 2-183 correspond to the resistor recommended when a single device is used and to the equivalent
parallel resistor when multiple devices are connected via a JTAG chain.
In critical applications, an upset in the JTAG circuit could allow entering an undesired JTAG state. In such
cases, Microsemi recommends tying off TRST to GND through a resistor placed close to the FPGA pin.
Note that to operate at all VJTAG voltages, 500  to 1 k will satisfy the requirements.
Special Function Pins
NC
No Connect
This pin is not connected to circuitry within the device. These pins can be driven to any voltage or can be
left floating with no effect on the operation of the device.
DC
Don't Connect
This pin should not be connected to any signals on the PCB. These pins should be left unconnected.
NCAP
Negative Capacitor
Negative Capacitor is where the negative terminal of the charge pump capacitor is connected. A
capacitor, with a 2.2 µF recommended value, is required to connect between PCAP and NCAP.
PCAP
Positive Capacitor
Positive Capacitor is where the positive terminal of the charge pump capacitor is connected. A capacitor,
with a 2.2 µF recommended value, is required to connect between PCAP and NCAP.
PUB
Push Button
Push button is the connection for the external momentary switch used to turn on the 1.5 V voltage
regulator and can be floating if not used.
PTBASE
Pass Transistor Base
Pass Transistor Base is the control signal of the voltage regulator. This pin should be connected to the
base of the external pass transistor used with the 1.5 V internal voltage regulator and can be floating if
not used.
PTEM
Pass Transistor Emitter
Pass Transistor Emitter is the feedback input of the voltage regulator.
This pin should be connected to the emitter of the external pass transistor used with the 1.5 V internal
voltage regulator and can be floating if not used.
XTAL1
Crystal Oscillator Circuit Input
Input to crystal oscillator circuit. Pin for connecting external crystal, ceramic resonator, RC network, or
external clock input. When using an external crystal or ceramic oscillator, external capacitors are also
recommended (Please refer to the crystal oscillator manufacturer for proper capacitor value).
If using external RC network or clock input, XTAL1 should be used and XTAL2 left unconnected. In the
case where the Crystal Oscillator block is not used, the XTAL1 pin should be connected to GND and the
XTAL2 pin should be left floating.
2-230
Revision 4