Achronix Speedster22i User Macro Guide User Manual
Page 191
Multipliers
BMACC56
Speedster22i Macro Cell Library
PAGE 174
rst_b
input
Data Input B Register Reset (active-low). Asserting input rst_b per-
forms a synchronous reset of the Data Input b register upon the next
active edge of the clock, and will set the register to the value defined
by the rst_value_b parameter.
rst_sub
input
Subtract Input Register Reset (active-low). Asserting input rst_sub
performs a synchronous reset of the Subtract Input Register upon
the next active edge of the clock, and will set the register to the value
defined by the rst_level_sub parameter.
rst_cin
input
Carry In Input Register Reset (active-low). Asserting input rst_cin
performs a synchronous reset of the Carry In Input Register upon the
next active edge of the clock, and will set the register to the value
defined by the rst_level_cin parameter.
rst_mask_adda
input
Adda Mask Input Register Reset (active-low). Asserting input
rst_mask_adda performs a synchronous reset of the Adda Mask
Input Register upon the next active edge of the clock, and will set the
register to the value defined by the rst_level_mask_adda parameter.
rst_dout
input
Dout Output Register Reset (active-low). Asserting input rst_dout
performs a synchronous reset of the Dout and Cout output registers
upon the next active edge of the clock, and will set the dout register
to the value defined by the reset_dout parameter. and will set the
cout register to the value defined by the rst_level_cout parameter.
cascade_in[55:0]
input
Cascade In. The cascade input allows the 56-bit cascade_out output
of the previous BMACC56 block to be connected to the adda input of
the add/sub block. The cascade_out to cascade_in flows from the
bottom of the Speedster22i device to the top.
clk
input
Clock. Data is clocked into the input and output registers at the
active edge of the clock input. The active edge of the clock input is
selected by setting the clock_edge parameter to the appropriate
value.
dout[55:0]
output
Data Out. The dout[55:0] output is the 56-bit signed two’s comple-
ment output, where bit 55 is the most significant bit.
cout
output
Carry Out. The cout bit is set high if a carry was generated out of the
add/sub block.
cascade_out[55:0]
output
Cascade Out. Cascade_out may be fed to the next BMACC56 blocks
adda input. This can be used to help in the formation of sum-of-
products of multiple BMACC56 blocks when the sel_cascade_out
parameter is set to zero.
Name
Type
Description