Detailed Specifications
2- 10
R e v i sio n 1 8
User-Defined Supply Pins
VREF
Supply Voltage
Reference voltage for I/O banks. VREF pins are configured by the user from regular I/O pins; VREF pins
are not in fixed locations. There can be one or more VREF pins in an I/O bank.
Global Pins
HCLKA/B/C/D
Dedicated (Hardwired) Clocks A, B, C and D
These pins are the clock inputs for sequential modules or north PLLs. Input levels are compatible with all
supported I/O standards. There is a P/N pin pair for support of differential I/O standards. Single-ended
clock I/Os can only be assigned to the P side of a paired I/O. This input is directly wired to each R-cell
and offers clock speeds independent of the number of R-cells being driven. When the HCLK pins are
unused, it is recommended that they are tied to ground.
CLKE/F/G/H
Routed Clocks E, F, G, and H
These pins are clock inputs for clock distribution networks or south PLLs. Input levels are compatible with
all supported I/O standards. There is a P/N pin pair for support of differential I/O standards. Single-ended
clock I/Os can only be assigned to the P side of a paired I/O. The clock input is buffered prior to clocking
the R-cells. When the CLK pins are unused, Microsemi recommends that they are tied to ground.
JTAG/Probe Pins
PRA/B/C/D
Probe A, B, C and D
The Probe pins are used to output data from any user-defined design node within the device (controlled
with Silicon Explorer II). These independent diagnostic pins can be used to allow real-time diagnostic
output of any signal path within the device. The pins’ probe capabilities can be permanently disabled to
protect programmed design confidentiality. The probe pins are of LVTTL output levels.
TCK
Test Clock
Test clock input for JTAG boundary-scan testing and diagnostic probe (Silicon Explorer II).
TDI
Test Data Input
Serial input for JTAG boundary-scan testing and diagnostic probe. TDI is equipped with an internal 10 k
Ω
pull-up resistor.
TDO
Test Data Output
Serial output for JTAG boundary-scan testing.
TMS
Test Mode Select
The TMS pin controls the use of the IEEE 1149.1 boundary-scan pins (TCK, TDI, TDO, TRST). TMS is
equipped with an internal 10 k
Ω pull-up resistor.
TRST
Boundary Scan Reset Pin
The TRST pin functions as an active-low input to asynchronously initialize or reset the boundary scan
circuit. The TRST pin is equipped with a 10 k
Ω pull-up resistor.
Special Functions
LP
Low Power Pin
The LP pin controls the low power mode of Axcelerator devices. The device is placed in the low power
mode by connecting the LP pin to logic high. To exit the low power mode, the LP pin must be set Low.
Additionally, the LP pin must be set Low during chip powering-up or chip powering-down operations. See
NC
No Connection
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.