10.1.1.3 Accumulator Parameter Description

The following table describes all the parameters of an accumulator.

Table 10-3. Parameter Description
Parameter	Family	Value	Function
WIDTHA	ProASICPLUS	2–128	Word length of DataA, DataB and Sum
	Axcelerator	2–156
	All others	2–32
MAXFANOUT	ProASICPLUS	0	Automatic choice
MAXFANOUT	ProASICPLUS	2–16	Manual setting of Max. Fanout
CI_POLARITY	ALL	0 1 2	Carry-in polarity (active low, active high and not used)
CO_POLARITY	ALL	0 1 2	Carry-out polarity (active low, active high and not used)
CLR_POLARITY	—	0 1 2	Asynchronous reset (active high, active low and not used)
EN_POLARITY	—	0 1 2	Asynchronous enable (active high, active low and not used)
FFTYPE	ALL except Flash	REGULARTMRB	FF type used (Regular, Triple Voting)
CLK_EDGE	—	RISE FALL	—

Note:

The Brent-Kung Accumulator extends the ranges from 32 to 128 bit for SX and SX-A.
TMR is Triple Module Redundancy. Choosing this option enables TMR Flip-Flops that are used to avoid Single Event Upsets (SEUs) for Rad-hard Designs. Choosing this option causes the Sequential resource usage to be tripled in families where no TMR is implemented in silicon.